Based on these findings, CSC theory as well as EMT program, we propose a hypothesis that overexpression of stem cell markers Oct4 and Nanog, which maintain self-renewal and proliferation in embryonic stem cells, may also maintain HCC cell self-renewal, proliferation, metastasis through initiating CSC-like properties, and promoting EMT. This evidence concerns the gene POU5F1 and hepatocellular carcinoma.