POU5F1 and cancer: Several studies have shown that high levels of expression of EMT-inducing transcription factors ZEB1/2, SNAI1/2, TWIST1/2, and FOXC2 in cancer cells trigger the expression of stemness factors such as SOX2, BMI1, and OCT4 and enhance the ability to self-renew and to form mammospheres, all of which are characteristics of CSCs [29–32].