Altogether, data obtained from clinical specimens show that in CaP and BrCa patients, EMT and MET-like changes accompany the formation of LN metastasis and that overexpression of MDM2 and underexpression of MDMX together with the prevalence of epithelial phenotype in metastatic lesions is the most frequently observed phenomenon. This evidence concerns the gene MDM4 and invasive breast carcinoma.