“…IL-4 and IL-13, which are cytokines highly produced in Th2/eosinophilic asthma, can downregulate ACE2 expression in airway epithelial cells (Kimura et al, 2020;Song et al, 2020), whereas, TNF, IL-12, and IL-17A, which are cytokines highly produced in Th17/neutrophilic asthma and COPD (Alcorn et al, 2009), can upregulate ACE2 expression in in vitro BEAS-2B cells (Song et al, 2020). In addition, circulating soluble angiotensinconverting enzyme 2 (sACE2) is upregulated in the blood of asthmatic patients (Ayada et al, 2015); hence, sACE2 could act as a competitive interceptor, limiting SARS-CoV-2 attachment to airway cell membranes (Batlle et al, 2020).…”