ATP11A and idiopathic pulmonary fibrosis: Cycles of alveolar damage, recruitment of monocytes, and their differentiation into monocyte-derived alveolar macrophages occur repeatedly during IPF.74 Specifically, M2 macrophages promote fibrosis, possibly through secretion of TGF-beta82 and other profibrotic factors.74 ATP11A, or ATPase Phospholipid Transporting 11A, is a member of the P4-ATPase family of lipid flippases, responsible for translocating aminophospholipids on the cellular membrane.83,84 We propose two mechanisms that could explain ATP11A’s involvement in the pathogenesis of IPF and COVID-19.