As shown in Table 3, branebrutinib is equally cytotoxic to P-gp-overexpressing human ovarian NCI-ADR-RES cancer cells, human epidermal KB-V-1 cancer cells, human K562/i-S9 chronic myelogenous leukemia cells, and the corresponding drug-sensitive parental OVCAR-8, KB-3-1, and K562 cells. This evidence concerns the gene PGP and cancer.