ABCG2 and nonpapillary renal cell carcinoma: Several studies reported that the ABC transporters, ABCB1 (Watanabe et al., 2017) and ABCG2 (Watanabe et al., 2017; Reustle et al., 2018) were correlated with drug resistance in ccRCC, while ABCG2 (Low et al., 2016) was correlated with drug-induced toxicity.