By isolating certain genes in a cancer cell, called oncogenes, researchers hope to be able to affect the lifespan and proliferation of certain cancer cells. Oncogenes are genes in a cancer cell that influence the mutation, amplification, and proliferation of the cell. Anti-oncogenes are genes that may "turn off" cancer cells and transform them back to normal cells. In this illustration of the genetic engineering, a strand of DNA (yellow) interferes with the messenger RNA's (orange) sequence in order to disrupt and alter the genetic structure of the tumor.