FABP4 and idiopathic pulmonary fibrosis: The results suggest a strong similarity between our subsets and those of others, where: our homeostatic FABP4hi AM population aligns with FABP4+, AMφ-2, Mφ-0, and Mφ2 populations; our pro-fibrotic population aligns with the CD163/LGMN-Mφ, Mφ-1, Mφ-fibrosis, SPP1+Mφ, and SPP1+Mφ-IPF populations.