Remarkably, effectively better differentiation between CTD-ILD+ and IPF was confirmed for a 5-biomarker signature consisting of MMP-3, MMP-7, MMP-9, MMP-10, and TIMP-1 in RA as well as for the MMP-7 and MMP-10 combination in SSc. The gene discussed is TIMP1; the disease is idiopathic pulmonary fibrosis.