POU5F1 and embryonal carcinoma: Taylor-Weiner et al. [157] indeed showed that both NANOG and POU5F1 were not expressed in tumors obtained from cisplatin-resistant metastases, like for the in vivo mouse model of a sensitive and resistant disease, where the xenografts originating on cisplatin-resistant cell lines exhibited areas with cells of embryonal carcinoma morphology, but with the absence of OCT3/4 expression [53].