ACE2 and COVID-19: There is a significant release of inflammatory factors in patients with severe COVID‐19, and the release of these factors may originate from the invasion of alveolar macrophages by SARS‐CoV‐2 via angiotensin‐converting enzyme 2, thus resulting in the release of interleukin‐6 and TGF‐β from alveolar macrophages [65, 66].