Lyn associates with PKC-δ and regulates PKC-δ Y311 phosphorylation on GPVI stimulation. Washed aspirin-treated human and indomethacin-treated murine platelets were used. Human platelets were stimulated with 500 μM AYPGKF or 100 ng/mL CVX and immunoprecipitated with total PKC-δ and probed for total Lyn (A). Washed indomethacin-treated murine platelets from Lyn^−/− mice and corresponding WT littermates were stimulated with 60 ng/mL CVX or 20 μg/mL collagen for 1 minute. The samples were then lysed with sample buffer containing DTT and probed for PKC-δ Y311 (B). Total PKC-δ served as a lane-loading control in this experiment.