Conversely, type I interferon signaling and production was significantly upregulated amongst SPP1hi and FABP4hi macrophages in SSc-ILD (Figures 2E, H), compared to IPF, including expression of multiple interferon-induced transmembrane proteins, IFI35, ISG15, and EGR1 within the SPP1hi macrophages and TBK1, CHUK, and PTPN11, amongst others, within the FABP4hi macrophages. This evidence concerns the gene TBK1 and interstitial lung disease.