RHOA and septic shock: Both whole blood impedance aggregometry and Western blot analysis of P-[Ser19]MLC20 and the ROK substrate P-[Thr855]-MYPT were performed to test the following hypotheses: 1) whole blood aggregation of platelets is attenuated in patients with septic shock, 2) platelet aggregation in septic shock patients correlates with illness severity indexed by the SOFA and APACHE II scores, and 3) platelet aggregation in septic shock patients is associated with reduced (i) [Ser19]MLC20 phosphorylation and (ii) RhoA/ROK-mediated inhibition (Thr855 phosphorylation) of myofilament-associated MLCP.