TP53 and cancer: Since IGFBP-3 can act as a pro-apoptotic factor following DNA damage, even in the absence of p53 [8] or in the presence of mutant p53 (e.g. the L194F mutation in T47D cells) [29], it is possible that oncogenic forms of p53 might suppress IGFBP-3 and confer a survival advantage on a cancer cell under circumstances where IGFBP-3 is pro-apoptotic.