The well documented role of RhoA/Rho kinase signaling for the inhibition of MLC phosphatase and Ca2+ sensitization (Somlyo and Somlyo, 2003) could suggest that Ca2+ sensitization of vascular smooth muscle cells contributes to the molecular mechanism for the increase in vascular tone and/or systemic vascular resistance that produces hypertension. Here, RHOA is linked to hypertensive disorder.