RHOA and pulmonary arterial hypertension: Accumulating evidence shows that RhoA, a member of the Ras homolog gene family, and its downstream effectors, the Rho kinases (ROCKs), mediate the pathogenesis of PAH through their pro-proliferative contributions (Nagaoka et al., 2006; Guilluy et al., 2009; Connolly and Aaronson, 2011).