Role of Rap1 GTPase signaling in TEG. Blood samples were analyzed from WT mice (n=8), mice with global deficiency in CalDAG-GEFI and P2Y12 (Cdg1−/− × P2ry12−/−, n=4) or mice with megakaryocyte/platelet-specific deletion of Rap1b alone (Rap1bmKO, n=4) or both Rap1a and Rap1b (Rap1a/bmKO, n=5). (A-C) TEG parameters: R time (A), α-angle (B) and MA (C). (D) Representative TEG traces. Data shown as mean ± SD. Statistical significance was determined by one-way ANOVA with Tukey’s multiple comparison test. Symbols directly over bars represent significance compared to control. **P< .01, ***P<0.001, ****P < .0001.