PROM1 and neoplasm: In order to address the mechanism of CD133 positive tumor cells showing strong resistance to chemotherapeutic drugs, both CD133 positive cells and CD133 negative were collected by FACS sorting from the three primary cultured cells (No. 66, No. 377 and No. 1049) and used real-time PCR to investigate the expression of multi-drug resistance and DNA mismatch repair related genes, as well as genes related to inhibiting cell apoptosis within these two populations.