ABCG2 actively effluxes a wide variety of chemically and structurally unrelated compounds from cells including doxorubicin, etoposide, and 5-FU; ABCG2 overexpression in tumor cells confers multidrug resistance to a multitude of anti-cancer drugs levels [17, 43] and a lot of work has been going on to understand and successfully target the ABCG2 induced MDR. The gene discussed is ABCG2; the disease is cancer.