ACVR2A and chronic kidney disease: Furthermore, the ActRIIA ligand trap (activin A receptor blocking ligand) RAP-011 given in the CKD mouse model triggered a decrease in the activin A level, increased the contractile effect of vascular smooth muscle, increased the expression of cell-specific proteins in the aorta, reduced the osteoblast count, and lessened the degree of atherosclerotic intimal calcification.