Apatinib, an oral small molecular tyrosine kinase inhibitor targeting VEGFR-2, has shown strong anti-cancer effect as well as the capacity of reversing multidrug resistance (MDR) induced by breast cancer resistance protein, MDR-associated protein 1, and MDR protein 1 (Mi et al., 2010; Tong et al., 2012; Yang et al., 2020). The gene discussed is KDR; the disease is cancer.