SMA4 is a selective PKG1α activator with basal EC50 value of 29 μM. SMA4 facilitates phosphorylation of the known PKG1 substrate, vasodilator-stimulated phosphoprotein (VASP), and inhibits human pulmonary arterial smooth muscle cells (hPASMC) proliferation. SMA4 can be used for cardiovascular disease research[1].