POU5F1 and hepatocellular carcinoma: Consistent with these reports, our previous data showed that the activation of the PI3K/Akt pathway can promote PGC proliferation and maintain Oct-4 expression in embryonic germ cells (Kimura et al., 2003; Moe-Behrens et al., 2003; Kuo et al., 2018) and that niche IL-6/IGF-IR signaling causes poor prognosis of hepatitis B virus (HBV)-related HCC because of Oct-4/Nanog expression (Chang et al., 2015).