Tumor Suppressor	Normal Function		Alteration in Cancer		Associated Cancers
p53	Cell cycle checkpoints,   apoptosis		Mutation, inactivation by viral   oncogene products		Brain, lung, colorectal,   breast, many types
RB1	Cell cycle checkpoints, binds   E2F		Mutation, deletion, inactivation   by viral oncogene products		Retinoblastoma,   osteosarcoma, many types
APC	Cell-cell interaction		Mutation		Colorectal cancers, brain, thyroid
Bcl2	Apoptosis regulation		Overexpression blocks apoptosis		Lymphomas, leukemias
XPA-XPG	Nucleotide excision repair		Mutation		Xeroderma pigmentosum,   skin cancers
BRCA2	DNA repair		Point mutations		Breast, ovarian, prostate   cancers