We grouped genes with similar expression trends, obtaining a consensus of 13 different expression trends related to various biological functions, as shown in the clustering results in Fig. 2C. We observed that genes in Cluster 1 of IPF-MΦ exhibited significantly high expression levels, and these genes were highly enriched in biological functions such as Th1 and Th2 cell differentiation, PPAR signaling pathway, pertussis, complement, and coagulation cascades, renin-angiotensin system, and regulation of fat breakdown in adipocytes, among others. Here, PPARA is linked to idiopathic pulmonary fibrosis.