(A) Structures of afatinib (Af)6, WZ4002 (WZ)5, CO-1686 (CO)7, and AZD-9291 (AZ)8. (B,C) Fold-increase in expression-corrected ReAsH fluorescence over background of cells expressing CCX-1 or CCX-10 variants in the presence or absence of TKI. Error bars, s.e.m. **** p < 0.0001, *** p < 0.001, ** p < 0.01, * p < 0.05 from one way ANOVA with Bonferroni post-test.