The seven viruses that cause human cancers

Roughly 1 in 5 cancers are caused by viruses

About 20% of cancers are caused by viruses, with seven specific oncoviruses causing between 10% and 15% of cancers worldwide. These include human papillomavirus and hepatitis B and C viruses, which can lead to diseases such as cervical and liver cancer. Understanding the mechanisms of these viruses is crucial for prevention and treatment strategies.

Every virus is classified into 7 groups based on genetic differences

Viruses infecting humans have been named based on symptoms ("chickenpox") or the location or animal in which they were first discovered ("Bolivian Haemorrhagic Fever" and "Monkeypox"). For clarity among scientists and to reduce stigma, virologists classify the 15,000 known viruses (270 of which infect humans) by their basic genetic material.

Seven known types of coronaviruses have jumped from animals to humans

Coronaviruses, including SARS-CoV-2, belong to a large family of viruses characterized by their crown-like appearance under a microscope, due to spike proteins on their surface. While thousands are believed to exist in animals, only seven are known to have made the jump to humans.

The HPV vaccine reduces cervical cancer rates by 90% or more

Cervical cancer is the fourth most common cancer in women globally. Almost all cases (99%) are linked to infection with high-risk human papillomaviruses. However, cervical cancer is both treatable and preventable—and we may be able to prevent most cases through vaccination.

Up to 8% of the human genome consists of ancient viral DNA

Human endogenous retroviruses are remnants of infections that affected human primate ancestors millions of years ago and were passed on by infiltrating sperm and egg cells. Studies have shown that this DNA may play a role in immune responses and in placental formation.

Cancer is runaway growth of abnormal, mutated cells

Cancer cells have mutations in their DNA that allow uncontrolled growth and division, dodge usual mechanisms of cell death, and can often spread throughout the body. This is, in part, why the disease is so difficult to treat, with a wide variety of mechanisms and types that poses unique challenges.

Many cancers arise from genetic mutations inherited from your parents

These mutations may happen in response to environmental or lifestyle factors, or may be passed down through family members. Genetic testing can be important in catching certain family cancers early and ensuring patients receive the right treatment for their disease.

How does cancer spread through the body?

Cancer usually begins with one tumor, but it can spread to other organs if not removed. This video breaks down how cancer moves to these new areas and why some organs are more likely to get infected than others.

Explore interactive global maps of cancer prevalence

Cancer is a ubiquitous disease, with populations across the globe having incidence rates that reflect various risk factors. The Cancer Atlas lets users explore a comprehensive global overview of cancer statistics, including incidence, mortality, prevalence, and survival rates across various regions and Human Development Index categories.

Epstein-Barr virus—the cause of 'kissing disease' mononucleosis—may be the leading cause of MS

A Harvard study with data from more than 10 million US military personnel found that people that contracted Epstein-Barr virus had a roughly 32-fold increased risk of developing multiple sclerosis. The work, published in 2022, found that Infection of the virus preceded MS onset by a median of five years, raising questions about better Epstein-Barr virus management and potential disease prevention.

Explore 3D models of some of the most dangerous viruses

Everyone has come in contact with common viruses—typically something like influenza (the common flu)—but sometimes they encounter more dangerous strains. While we're familiar with the symptoms that manifest, it wasn't until the advent of advanced microscopy that scientists could pin down the exact structure and behavior of various viruses.

Vector-borne diseases kill more than 700,000 people globally each year—and are growing

The diseases with the greatest potential to spread widely aren't the ones that quickly kill human hosts. Instead, the best hosts or reservoirs for vector-borne diseases would be chronically ill over the long term, increasing the likelihood that the pathogen could be transmitted to others.

Alcohol is responsible for 5% of cancer cases and 4% of cancer deaths in the US

Alcohol consumption is linked to at least eight different types of cancer, including liver, breast, and throat. The risk comes from ethanol, which turns into DNA-damaging acetaldehyde. Experts recommend limiting intake or quitting altogether to reduce long-term health risks.

Evidence of cancer has been found in a 1.7-million-year-old fossil

Cancer has existed as long as humans have, with some of the earliest evidence found among fossilized bone tumors, human mummies in ancient Egypt, and ancient manuscripts. The oldest example was uncovered in a toe—millions of years old—from an ancestor of modern-day humans.

Watch how viruses like Ebola can spill over from animals to humans—and vice-versa.

mRNA vaccines alter immune response, not DNA, to combat diseases like cancer

These vaccines—developed using techniques to create COVID vaccines—are now being tested for cancer treatment and have shown improved survival rates in patients with lung cancer. Scientists believe the research involved in developing these vaccines has opened the door to new and effective personalized cancer treatments in the future.

Receptors on the cell surface are key to whether a virus is successful

Viral receptors are key regulators of host range, tissue tropism, and viral pathogenesis—basically, the door locks on cells allowing viruses to invade, if they have the right key. How this process works at the microscopic level determines whether a virus is able to trigger a widespread illness in the host.

Computer viruses' hijacking abilities led them to be named after biological viruses

Just as their counterparts infect cells and take control of cellular processes to replicate endlessly, computer viruses cannot replicate on their own and must copy their code into host software before duplicating when the program or file is opened. The term "virus" comes from the Latin word for "venom."

Marburg virus, related to Ebola, is also extremely deadly, and has no available vaccine.

A new type of immunotherapy focuses on healthy cells hijacked by tumors

Purdue University scientists are at work on a new cancer treatment that attacks immune system cells that feed and protect cancer cells rather than attacking them. The immunotherapy process promises to become a universal treatment for solid tumors. Thus far, the treatment has been tested and shown to work on human tumor cells in the laboratory and animal models.

What are universal vaccines?

As viruses mutate and develop, vaccines have to adapt, leading to regular recommended injections like flu shots. Researchers are working to develop universal vaccines that aim to protect against multiple virus variants if not entire virus families. These vaccines work by creating broadly neutralizing antibodies (bnAbs) that target aspects of viruses that don't typically mutate and are integral to the virus' survival.

The 1957 and 1968 influenza pandemics caused millions of deaths worldwide

The 1957 H2N2 pandemic spread from East Asia, killing more than 1M globally, while the 1968 H3N2 pandemic began in Hong Kong and caused a similar toll, with both strains rapidly moving across continents.

Only one strain of wild poliovirus continues to infect humans

Three strains of polio used to regularly infect humans, but two of the strains were declared eradicated in 2015 and 2019, respectively. In 2019, world health leaders estimated complete polio eradication—if achieved—would save $14B by 2050.

Autoimmune disease prevalence and incidence are on the rise—but no one knows why

Researchers theorize that environmental factors, including shifts to less healthy diets, air pollution, infections, stress, climate change, and exposures to xenobiotics—substances like pesticides, plastics, and toxins that incite immune responses—may all be fueling epigenetic changes to our bodies that make people's immune responses go awry.

Larger animals like giraffes, elephants, and blue whales have developed a unique defense against cancer, a phenomenon known as Peto's Paradox

Humans are more genetically similar to cats than to dogs

While humans are not closely related to either cats or dogs from an evolutionary standpoint, scientists find that human and cat chromosomes are organized more similarly to each other than human and dog chromosomes, making cats a better model for studying human diseases.

Mycotoxins are toxic compounds produced by fungi—some show up in food

About a quarter of the world’s agricultural products are contaminated with mycotoxins. Some of these compounds can cause serious health problems, including cancer, so the US government has set up monitoring programs to detect them in our food and in animal feed. Humans can become ill if they eat contaminated food, but also if they ingest products from animals that had previously consumed these toxic compounds, such as milk from a cow that ate contaminated corn.

The coronavirus pandemic sparked theories about the dangers of 5G

COVID-19 spreading around the same time as the rollout of 5G sparked conspiracy theories and outrage that the new wireless technology was harming people and the environment. (Some users may experience a paywall.)

Hookworm infection, though risky, may help fight certain autoimmune conditions by tamping down the immune system's inflammatory response.

The first line of 'immortal' human cells, which can divide indefinitely and are used in scientific research, was nonconsensually taken from a Black woman.

Radioactive elements can introduce software errors because the ionizing radiation they produce can detach electrons from atoms, and computer code relies on the distribution of electrons.

Tattoos remain visible on your skin thanks to immune cells called macrophages

Visualize how CRISPR-Cas9—a type of immune system used by single-celled organisms to attack invasive viruses—targets and makes precise changes to a gene's DNA.

Louisiana's 'Cancer Alley' is infamous for having some of the highest industrial pollution, toxic air emissions, and cancer risks in the US.

View the ten deadliest tornadoes in US history.

The Nasdaq's 'Magnificent 7' companies are responsible for roughly 40% of the Nasdaq 100 index's gains, while the remaining 93 companies account for the other 60%.

Listen to an in-depth conversation on the links between Parkinson's disease and herbicide exposure and the challenging pace of scientific investigation.

Elk Cloner, the first computer virus to spread in public, was written as a practical joke by Richard Skrenta, a Pittsburgh high school student.

As of 2025, the most cited papers in science include a review of graphene, methods to improve image recognition, streamlining electron density calculations, and optimizing protein studies.

Poison ivy can cause rashes year-round since all parts of the plant contain urushiol, the oil that triggers our allergic response.

Volcanoes 'die' when their supply of magma runs out, if they are shifted away from their underlying magma reservoir, or if they get clogged by collapsing or their magma cooling back into rock.

The Dracula character, now seen as the vampire archetype, was inspired by a seafood-induced nightmare its creator experienced.

Venture capital is a form of funding provided to early-stage companies with high growth potential, typically in exchange for an equity (or ownership) stake

The United States is one of only around two dozen countries with a fully federal system of government, in which power is divided between national and state governments.

While the sun's gravity keeps the planets in orbit, their gravity also pulls on the sun, causing it and everything else in the solar system to orbit around a mutual balance point called the barycenter—the true center of the solar system.

Some researchers have labeled nomophobia, the fear of being without your phone, as 'the phobia of the 21st century.'

Fireworks-related ER visits are on the rise—in 2024, they increased by 52% as compared to the prior year.

See 33 images that became central to huge scandals, including a young Charles and Camilla, Michael Jackson's baby on a hotel balcony, and Hugh Grant's mugshot.

The Russia-Ukraine conflict is the largest ground war in Europe since World War II in casualties, forces mobilized, and displacement of civilians.

Children are now three times more likely to say they want to be a YouTuber when they grow up than an astronaut, with some even attending 'YouTube camps' that teach kids how to create content for the platform.