P-glycoprotein (P-gp/ABCB1) is an ATP-binding cassette (ABC) transporter that extrudes various anticancer drugs (e.g., paclitaxel, etoposide, vincristine, and doxorubicin) from cancer cells, as well as various endogenous molecules (Kathawala et al., 2015). Here, PGP is linked to cancer.