POU5F1 and Familial prostate cancer: The upregulation of Oct3/4 expression could be correlated with the enhanced HIF-2α expression under hypoxia and this observation is consistent with previous findings that HIF-2α binds to the promoter of Oct3/4 and induces its expression and activity directly [45], supporting a potential role for the interaction of HIF-2α and Oct3/4 in prostate cancer cells response to hypoxia.