The PI3K inhibitor BAY-1082439 was able to down regulate P-gp and BCRP expression, and nonviral transgenic vector-mediated CRISPR/Cas9 knockdown of PI3K in non-small cell lung cancer H460 cell line and its resistant subline H460/MX20 110 α And 110.0 β Subunit, leading to downregulation of P-gp and BCRP and reversing P-gp-mediated drug resistance (Zhang L. et al., 2020). The gene discussed is ABCG2; the disease is non-small cell lung carcinoma.