ALDH1A1 and colorectal carcinoma: Targeting of CSCs could be achieved in CRC through the various cell surface markers associated with self-renewal, including CD133, CD166, CD44, CD24, beta1 integrin-CD29, Lgr5, EpCAM (ESA), ALDH-1, Msi-1, DCAMLK1 or EphB receptors (18, 21).