ACO1 and idiopathic pulmonary fibrosis: The following is a plausible profile of actively proliferating VECs in IPF lungs: i.e. a metabolic state where i) ACO1 actively mediates glutaminolysis and reductive carboxylation in proliferating vascular endothelial cells and ii) only specific linear portions of the mitochondrial TCA cycle actively work to fulfill the anabolic requirements (Mullen et al., 2011; Hollinshead and Tennant, 2016; Huang et al., 2017; Kim et al., 2017; Wong et al., 2017) (Supplementary Figure SE7).