POU5F1 and cancer: A weaker expression of OCT4, SSEA4 and SOX2 was seen by IHC, but no difference was found in the various subtypes of LC-42 cells (Figure 2A), which is in line with the real-time PCR analysis of Nanog, Oct4 and Sox2. As a physiological process that occurs during various stages of embryogenesis, Epithelial-mesenchymal transition (EMT) program has been reported also to play a crucial role during cancer invasive growth and metastases [29].