(A) Correlation analyses between OCT2 inhibition and inhibition of OCT2-A270S, the hepatic homologue OCT1, and the apical organic cation transporters MATE1 and MATE2-K. The prototypical organic cation transport inhibitor cimetidine is indicated by the arrows. (B) Venn diagram showing the overlapping inhibitors for OCT2, OCT1, MATE1 and MATE2-K. (C) Selectivity of inhibition for putative clinical inhibitors of OCT2. The concentration dependent inhibition of ASP+ uptake is shown for HEK293 cells stably expressing OCT2-Reference (closed circles), OCT2-A270S (open circles), MATE1 (upward pointing triangles), MATE2-K (downward pointing triangles) and OCT1 (open squares). Data are presented as mean ± s.d. (three separate samples from one representative experiment).