On the other hand, Xu et al. demonstrated that IRF6 was reduced in highly metastatic NPC cells, cancer stem-like NPC cells, and NPC animal models.261 IRF6 directly restricts ATP-binding cassette sub-family G member 2 (ABCG2) expression in NPC cell lines and NPC tissues, resulting in the inhibition of NPC cancer cell proliferation, colony formation, and self-renewal.261. This evidence concerns the gene ABCG2 and cancer.