PGP and cancer: Cytotoxicity assays revealed that the P-gp-overexpressing human KB-V1 epidermal cancer cell line was six-fold more resistant to ensartinib (Figure 1a), and the P-gp-overexpressing human NCI-ADR-RES ovarian cancer cell line was three-fold more resistant to ensartinib (Figure 1b) as compared to the parental KB-3-1 and OVCAR-8 cancer cell lines.