Recent studies have also shown that cell surface marker CD133 is used to prospectively enrich CSCs in CRC [20, 25, 26], therefore, we examined the expression of CD133 in purified small and large CRC cells using western blotting (Figure 3C), RT-qPCR (Figure 3D) and FACS (Figure 3E). The gene discussed is PROM1; the disease is colorectal carcinoma.