Furthermore, genes involved in FcγR-mediated phagocytosis (such as MARCKS, CDC42) and macrophage polarization phenotypes (including MSR1, MRC1) were enriched in FCN1h and SPP1hi lung macrophages from SSc-ILD patients (Fig. 1I, Supplementary Fig. S2B and Tables S5B–D, available at Rheumatology online). Here, MRC1 is linked to systemic sclerosis.