FASN and chronic obstructive pulmonary disease: These data were supported by analyzing available single-cell RNA-sequencing (scRNASeq) profiles of explanted lung tissue from patients with advanced COPD or control lungs, which demonstrated that FASN was predominantly enriched in a subpopulation of surfactant-producing AEC2 cells (associated with canonical “bulk” AEC2 markers such as SFTPA1, SFTPA2, and ETV5 and termed AT2B cells) (34) (Figure 2B and Supplemental Figure 2A).