Here, we examined the effect of 5-aza, which has not been examined in non-seminomatous GCT cells so far, on two distinct embryonal carcinoma (EC) cell lines, e.g., NCCIT bearing a mutant TP53, and 2102Ep, which has wild type TP53, in an in vitro model system of acquired cisplatin-resistance using isogenic, resistant sublines NCCIT-R and 2102Ep-R. This evidence concerns the gene TP53 and embryonal carcinoma.