Finally, we found that RA-ILD+ and SSc-ILD+ patients who had higher MMP and TIMP levels than the optimal cut-off previously defined for their discrimination from IPF (the worst prognostic ILD), did not predict poor survival (time to death or lung transplant) (Additional File 5: Figure S3, and Additional File 6: Fig. S4, respectively). This evidence concerns the gene TIMP1 and rheumatoid arthritis.