COVID-19 binds with their target cells through angiotensin-converting enzyme 2 (ACE2), which is expressed in various tissues and cell types, including pulmonary alveolar epithelial cells, small intestinal enterocytes, renal tubular cells and endothelial cells of blood vessels (Fang et al., 2020[4]; Sun et al., 2020[16]). Here, ACE2 is linked to COVID-19.