A particularly unpleasant form of cancer. It is a childhood cancer, leading to tumors in the eyes. The best treatment is the removal of the cancerous eye. Unfortunately, retinoblastoma almost always affects both eyes, so that you have a young child that must be surgically blinded. Even then, the child is susceptible to other types of cancers throughout life.
Researchers have discovered that retinoblastoma is caused by a genetic defect in the gene called pRB - which is named because of it's affect in retinoblastoma ("p"rotein "R"etino"b"lastoma). It is one of a number of protooncogenes, or genes which are frequently defective or affected in cancers. pRB plays a role in detecting DNA damage in cells.