POU5F1 and neoplasm: In this case, SORE6- or “non-CSCs” were able to convert to SORE6+ cells, gaining GFP expression and enhanced expression of stemness genes, suggesting certain factor(s) in the in vivo microenvironment triggered the subset of SORE6- cells to reprogram back to a stemness-like state, upregulating SOX2/OCT4 activity and possibly other stemness-related genes in order to maintain the capability of initiating tumor growth.