Cancer cells can become resistant to a broad spectrum of structurally and mechanistically distinct antitumor drugs with underlying molecular mechanisms, at least including diminished intracellular drug concentration via impaired drug influx and/or enhanced drug extrusion mediated by multidrug resistance (MDR) efflux transporters, and P-gp is the best characterized efflux pump known to play an important role in chemotherapeutic drug efflux in cancer cells (Dong et al., 2020). This evidence concerns the gene PGP and cancer.