C1QC and interstitial lung disease: Complement component genes (C1QA, C1QB, C1QC) were downregulated in SSc-ILD FCN1hi macrophages (Fig. 1G, Supplementary Table S5B, available at Rheumatology online) and gene ontology analysis revealed the phagosome pathway among the most enriched pathways (Fig. 1H), pointing towards a pro-phagocytic macrophage signature.