Angiotensin-converting enzyme 2 （ACE2） is an enzyme that can be found either attached to the membrane of cells （mACE2） in the intestines, kidney, testis, gallbladder, and heart or in a soluble form （sACE2）. Both membrane bound and soluble ACE2 are integral parts of the renin–angiotensin–aldosterone system （RAAS） that exists to keep the body's blood pressure in check. Soluble ACE2 lowers blood pressure by catalyzing the hydrolysis of angiotensin II （a vasoconstrictor peptide） into angiotensin （1–7） （a vasodilator） which in turns binds to MasR receptors creating localized vasodilation and hence decreasing blood pressure. This decrease in blood pressure makes the entire process a promising drug target for treating cardiovascular diseases. mACE2 also serves as the entry point into cells for some coronaviruses, including HCoV-NL63, SARS-CoV, and SARS-CoV-2. The SARS-CoV-2 spike protein itself is known to damage the endothelium via downregulation of ACE2.