Some tumors are related to viruses, such as cervical cancer, lymphoma and liver cancer. Viruses can cause tumors because some genes in their genomes can disturb the regulation of cell growth. Once the cells become cancerous, tumor cells will grow and multiply under certain conditions, and the number will increase rapidly, eventually forming tumors visible to the naked eye.

In some cases, due to infection, the host cells have changed materially and genetically. Infection can also lead to infection without killing the infected virus. A few human papillomavirus genes are active, and they can replicate the virus with cell division. Once the virus gene accidentally combines with the main cell gene, the disorder replication of virus protein will occur. These protein lead to uncontrolled division of host cells. Some viral proteins inhibit tumor suppressor genes, resulting in uncontrollable cell division. Without the products of tumor suppressor genes, the main cells will continue to replicate and divide, and as a result, tumors will breed, and only a few virus genes are needed to cause tumors.

So we must pay attention to our health.