People infected with HIV have a significantly higher risk of some types of cancer compared with uninfected people of the same age. Three of these cancers are known as "AIDS-defining malignancies" Kaposi sarcoma, cervical cancer & non-Hodgkin lymphoma. A detection of any one of these cancers marks the point at which HIV infection has progressed to AIDS. Most types of cancer begin when normal cells begin to modify and grow uncontrollably, forming a mass called a tumor. A tumor can be benign (noncancerous) or malignant (cancerous). The most important of cancer-related viruses are Human herpes virus 8, Epstein Barr virus, Human papillomavirus, Hepatitis B virus. Other less common types of cancer that may develop in people with HIV/AIDS are angiosarcoma (a type of cancer that begins in the lining of the blood vessels), anal cancer, liver cancer, mouth cancer, squamous cell carcinoma, throat cancer, lung cancer, colorectal cancer, and multiple types of skin cancer including basal cell carcinoma, testicular cancer, and melanoma.