POU5F1 and familial pancreatic carcinoma: In human pancreatic cancer cells, CD44+/CD133+/EpCAM+ CSC-like cells exhibited lower levels of let-7 expression [16], and this suppressed let-7 expression promoted the expression of pluripotency transcription factor, such as NANOG, SOX2, SOX9, OCT4, KLF4 and c-myc, to maintain CSCs.