CD41 expression, integrin αIIbβ3 activation and α granule secretion on c-Cbl KO and c-Cbl ^YF/YF platelets. (A) Washed platelets from WT, c-Cbl KO and c-Cbl^YF/YF mice were analyzed for αIIb expression with CD-41–FITC antibody. (B) WT, c-Cbl KO and c-Cbl^YF/YF were stimulated with the indicated dose of PAR 4 agonist AYPYKF for 15 minutes in the presence of FITC-labeled anti–P-selectin (CD62) to test α-granule secretion or with PE-labeled JON/A antibody to evaluate integrin αIIbβ3 activation (C). Graphs represent mean ± SEM of % positive cells of 3 different experiments.