(A,B) CHO-hP2Y12β-arrestin cells were transiently transected with mock-pcDNA3 or hChemR23 using FuGene transfection reagent for 48 hours, 37°C. Cells were plated (1×105 cells/well), and ADP (10−5 M) or ADP plus RvE1 (10−10 M – 10−8 M) were incubated for 60 minutes, 37°C. (A) Human ChemR23 transient transfection was monitored using flow cytometry. Histograms are representative of n=4. (B) Inhibition of P2Y12 by RvE1 was monitored in mock-pcDNA3 (grey bars) or hChemR23 (black bars) Values are mean ± SEM of n=4, * p<0.03, 2-way ANOVA with Bonferroni post testing. (C) Proposed Scheme for RvE1 actions on human platelets (see discussion for details).