ENPP2 and COVID-19: scRNAseq analysis of BALF cells from COVID-19 patients indicated a predominance of macrophages (100, 101), where ENPP2 mRNA expression was detected in monocyte-derived alveolar macrophages (Mo-AMs) (61), that have been shown to drive the development of BLM-induced pulmonary fibrosis in mice (105).