Changes in the abundance of MYPT1 and CPI-17 proteins are often associated with alterations in vascular contractile properties, including but not limited to: an increase in MYPT1 expression in the pulmonary vasculature with pulmonary arterial hypertension in the rat27,28, a decrease in MYPT1 and CPI-17 in mesenteric arteries from a mouse model of sepsis29, a decrease in aortic CPI-17 protein in the spontaneously hypertensive rat30, and a decrease in MYPT1 in mesenteric vessels following acute myocardial ischemia in rats31. The gene discussed is PPP1R14A; the disease is pulmonary arterial hypertension.