As a first approach to the correlation that may exist between p53 mutant proteins and the HER2 receptor expression, we evaluated the mRNA and protein levels of p53 and HER2 in a panel of human cancer cells: MCF-7 and HeLa cells harboring wild-type p53 (wtp53), Saos-2 with null expression of p53 (p53-null), as well as, C33A, SKBR-3 and OVCAR-3 harboring three of the most frequent p53 hot-spot mutations (p53R273C, p53R175H and p53R248Q). This evidence concerns the gene TP53 and cancer.