MUC1 and idiopathic pulmonary fibrosis: Evidence supporting the NEU1 – MUC1 axis included publications demonstrating that NEU1 regulates pulmonary collagen deposition, lymphocytosis, and fibrosis in human and mouse models of IPF (128), KL-6 serves as a diagnostic and prognostic biomarker for, and mediator of, IPF/ILD (125, 180–183), and most importantly, NEU1 pharmacologic inhibition reverses bleomycin-induced increases in MUC1-ED desialylation and shedding from the cell surface (48).