PGP and cancer: Reversal assays revealed that, at the highest non-toxic concentration of 500 nM, ensartinib had no significant effect on P-gp-mediated resistance to the P-gp substrates paclitaxel, vincristine or colchicine [53] in P-gp-overexpressing KB-V1 and NCI-ADR-RES cancer cell lines, and the P-gp-transfected MDR19-HEK293 cell line (Table 2).