Importantly, self-maintenance and persistence of the SPP1high subset is dependent on M-CSF/M-CSFR signaling (35), what correlates with their specific expression of MAFB (33, 34), the high number of MAFB+ CD68+ macrophages detected in pulmonary fibrosis patients (33, 34) and their expression of MAFB-dependent pro-fibrotic genes like LGMN (16, 36, 37). This evidence concerns the gene MAFB and pulmonary fibrosis.