Deletion of Cx57 impairs GPVI signaling in platelets.⁶²Gap27 (50 and 100 μg/mL) or scrambled peptide (S; 100 μg/mL) pretreated Cx57^+/+ wild-type (WT) and Cx57^−/− knockout (KO) washed platelets (4 × 10⁸ cells/mL) were stimulated for 90 seconds with CRP-XL (1 μg/mL) under nonaggregation conditions in the presence of indomethacin (20 µM), cangrelor (1 µM), MRS2179 (100 µM), and EGTA (1 mM). Samples were lysed in the Laemmli sample buffer, separated by SDS-PAGE, transferred to PVDF membranes, and tested for (A) total tyrosine phosphorylation, (B) Syk phosphorylation (Tyr^525/526), (C) LAT phosphorylation (Tyr²⁰⁰), (D) PLCγ phosphorylation (Tyr¹²¹⁷), and (E) PKC substrate phosphorylation. Representative blots for the phosphorylation levels are shown. The bar graph represents mean normalized phosphorylation values relative to actin or 14-3-3-ζ levels. Results are mean ± SEM (n ≥ 3). *P < .05; ***P < .001 (calculated by 1-way ANOVA).