Furthermore, the ability of MMP-2 and TIMP-1 serum levels to characterize RA-ILD+versus RA-ILD- was confirmed by ROC analyses (AUC: 0.7188, p = 0.0023 and AUC: 0.6599, p = 0.0273, respectively, Fig. 3A, Additional File 2: Table S2) determining > 169,948 pg/mL for MMP-2 and < 56,004 pg/mL for TIMP-1 as optimal cut-off values (Additional File 2: Table S2). The gene discussed is MMP2; the disease is rheumatoid arthritis.