Further, other common comorbidities including chronic obstructive pulmonary disease (COPD), asthma, and cardiovascular disease (CVD) were also found more severe symptom and prognosis in COVID-19 with high expression of ACE2 (Contoli et al., 2006; Shi et al., 2020; Wan et al., 2020). Here, ACE2 is linked to COVID-19.