ACE2 and asthma: An initial experimental study was carried out with the hypothesis that one possible explanation for the low prevalence of asthma and other allergic diseases in Covid-19 patients could be a reduced angiotensin-converting enzyme-2 (ACE2) gene expression in the airway cells of these patients (Jackson et al., 2020), but another experimental study has found opposite results (Sajuthi et al., 2020).