Fang et al. described a theory stating that since the coronavirus binds to its target through an angiotensin-converting enzyme 2 (ACE-2) expressed by epithelial cells in kidney, lung and blood vessels, the infection can facilitate an increased risk of developing severe COVID-19 in individuals who take ACE inhibitors and angiotensin II Type-I receptor blockers (ARBs) and also among diabetic patients as they tend to have an increase in ACE-2 expression [37–39]. Here, ACE is linked to infection.