Recently, the characteristics highly associated with severe COVID-19 and high mortality rate were reported, and included age, elevated plasma C-reactive protein (CRP), D-dimer levels, and troponin T, decreased plasma albumin levels, increased body temperature, raised SOFA score, elevated pulmonary angiotensin-converting enzyme 2 (ACE2) expression, reduced plasma lymphocyte amount, extended ground glass opacities on chest computed tomography, and a high prevalence of comorbidities, including diabetes mellitus (4-, , 7). Here, ACE2 is linked to diabetes mellitus.