PROM1 and colorectal carcinoma: Over the last few decades, multiple markers have been identified to reveal the CSC subpopulation in CRC distinguishing between cell surface markers, including Prominin-1 (CD133), CD44, CD166, EpCAM, EphB2, Lgr5, D26, CD44v6, and intracellular proteins, such as aldehyde dehydrogenase 1 (ALDH1), Bmi1, Musashi-1 (MSI-1) and doublecortinlike kinase 1 (DCLK1) [35,36].