The p53 tumor suppressor carries missense mutations in most human cancers, and are generally more stable and highly expressed than wt p53.29 This is not the case with the other two well-studied tumor suppressors Rb and APC as they have been shown to carry deletion and truncation mutations.29 Missense mutations are often associated with gain-of-function phenotypes; mt p53 in MDA-MB-231 has been reported to have the ability to interact with certain peptides in order to prevent apoptosis induction. Here, RB1 is linked to cancer.