SLC31A2 and neoplasm: Comparing to their non-neoplastic counterparts, CD133+/CD24+/CTR2+ cells could regenerate tumor in vitro in soft agar (small colonies), were more undifferentiated (expressed higher embryonic stem cell marker levels), and had an individual gene expression profile, in particular, CTR2 was identified as a cell membrane protein involved in cisplatin chemoresistance that could be used to discriminate this population from normal progenitors.