We first examined the effect of TP-3654 on ABCB1-mediated resistance to doxorubicin, paclitaxel and colchicine, three well-known substrate drugs of ABCB1 [42], in ABCB1-overexpressing NCI-ADR-RES, KB-V-1 cancer cells, and ABCB1-transfected MDR19-HEK293 cells. The gene discussed is ABCB1; the disease is cancer.