PLIN2 and idiopathic pulmonary fibrosis: Applying HIF signature or upregulated oxidative stress gene expression signatures to this dataset, we identified that, compared to fibroblasts and myofibroblasts, the HAS1 high and PLIN2+ cells, whose presence was almost exclusively derived from the IPF lung tissue, had significantly increased HIF and upregulated oxidative stress scores (Figure 8a–d) and that these two scores were significantly correlated (Figure 8e), consistent with an increase in pseudohypoxic HIF activity in these disease-specific mesenchymal cell types.