KLF4 and neoplasm: Cultured CSCs melanospheres demonstrate the Hh-driven CSC properties of increased levels of pluripotency factors, SOX2, NANOG, OCT4 and KLF4, and Hh pathway components, SHH, PTCH1, SMO, GLI2, GLI3, high ALDH activity, the ability to clonally expand in vitro and initiate tumours representing the primary tumour in vivo [137].