It has been known that FBP1 is involved in carcinogenesis via c-Myc-independent or -dependent pathways.32, 36, 38 Several studies demonstrated that the ABC family is a direct transcriptional target of the Myc family.39, 40, 41 To further explore whether the FBP/MYC/ABCG2 pathway contributed to the induction of SP cells in NPC, we performed Hoechst 33342 flow cytometry and found an apparent decrease of the number of SP when FBP1 was knocked down (Figures 3a and b), whereas Ko143 (a specific inhibitor of ABCG2) obviously inhibited the efflux of Hoechst 33342. The gene discussed is FBP1; the disease is nasopharyngeal carcinoma.