Scientists know that many things can damage genes, including carcinogens , viruses , heredity , or the aging process. Others thought that viruses caused tumors to develop. In the 1980s, it was determined that both carcinogens and viruses can produce cancer genes - also called oncogenes.
Oncogenes get their name from the Greek word 'onkos', which means lump or mass.
Researchers know that cancer cells are unresponsive to the usual signals that control the growth of normal cells. If the genes that help maintain the repair of DNA are lost or not functioning, the likelihood that a damaged gene will be repaired decreases drastically. Tumor cells often have defects in the way DNA gets repaired. Scientists have started to find ways to change patients' genetic material to fight or prevent disease. Gene therapy is the process of supplying cells with healthy copies of missing or flawed genes.