Cancer cells undergoing MDR were generally characterized by ectopic alteration of various pathways including PI3K/AKT and Wnt/β-catenin, which play an import role in the expression of ABC transporter and anti-apoptosis protein such as P-gp, BCRP, Survivin and Bcl-2 (25–30). The gene discussed is ABCG2; the disease is cancer.