Specifically, for instance, “third generation” ABCB1 modulators, such as elacridar (GF120918), laniquidar (R101933), zosuquidar (LY335979), and tariquidar (XR9576) with only nanomolar concentrations of the inhibitors required to inhibit ABCB1-mediated pumping of drugs out of tumor cells effectively. This evidence concerns the gene ABCB1 and neoplasm.