For example, ectopic expression of Oct4, Nanog, or c-Myc in lung cancer cells significantly increased the CD133-expressing subpopulation, oncosphere formation, tumorigenicity, and drug resistance, while knockdown produced the opposite effect, supporting the notion that iPSC factors play an essential role in high tumorigenicity and stem-like traits [7-9]. Here, POU5F1 is linked to lung cancer.