POU5F1 and neoplasm: To explore the potential correlation between AhR and Oct4 (encoded by the POU5F1 gene) expression, we compared their mRNA levels in two human pluripotent stem cell lines (embryonic stem cell (ESC) H1, embryonal carcinoma cell (ECC) NCCIT), five human cancer cell lines (HeLa, HepG2, U87, HT-29 and MCF-7) and three human non-tumour cell lines (HUVEC, LO2 and 293T; Fig. 1a).