Although Bunz et al. demonstrated in vitro that the apoptosis-inducing effect of 5-FU was almost abrogated when they deleted TP53 in the wild-type TP53 carrying human colon cancer cell, HCT116 [39], this situation is quite different from the actual clinical setting in which p53 function was knocked out not by homozygous deletion, but by missense mutation. Here, TP53 is linked to colonic neoplasm.