The multidrug-resistant cells overexpressing ABCB1 or ABCG2 are equally sensitive to almonertinib as their respective drug-sensitive parental cells. The cytotoxicity of almonertinib was determined in (A) parental pcDNA-HEK293 cells (open circles) and HEK293 cells transfected with human ABCB1 (MDR19, closed circles) or human ABCG2 (482R-5, open squares), (B) ABCB1-overexpressing multidrug-resistant NCI-ADR-RES human ovarian cancer cell line (closed circles) and its drug-sensitive parental OVCAR-8 cancer cell line (open circles), (C) ABCB1-overexpressing multidrug-resistant KB-V-1 human epidermal cancer cell line (closed circles) and its drug-sensitive parental KB-3-1 cancer cell line (open circles), (D) ABCG2-overexpressing multidrug-resistant H460-MX20 human lung cancer cell line (closed circles) and its drug-sensitive H460 cancer cell line (open circles), as well as (E) ABCG2-overexpressing multidrug-resistant A549-Bec150 human non-small lung cancer cell line (closed circles) and its drug-sensitive parental A549 cancer cell line (open circles). Points, mean values from at least three independent experiments; bars; S.E.M.