Although one postulated mechanism for a dominant effect of mutant p53 is through the inhibition of p63 and/or p73 (Di Como et al, 1999; Strano et al, 2000; Gaiddon et al, 2001), the apoptosis induced by mutant p53 knockdown in breast cancer cells is independent of the p63 or p73 function. This evidence concerns the gene TP53 and breast cancer.