In this work, we have studied H358 and MDA-MB-231, a p53-null lung cancer cell line and a p53 mutant breast cancer cell line, respectively, for which we have found similar patterns of Rlip-responsiveness as those seen with H520 and MCF7, which are p53-functional cell lines established from lung and breast cancer, respectively. This evidence concerns the gene TP53 and breast carcinoma.