To date, MMP7 alone or in combination with other molecules seems to have the potential to discriminate IPF versus non-IPF patients.[10–12] For example, the combination of plasma SP-D, MMP7, and osteopontin was recently demonstrated to enhance diagnostic accuracy to distinguish IPF from other idiopathic interstitial pneumonias, but importantly not with rheumatoid arthritis-associated ILD.[12] In addition, patients with chronic HP, another frequent IPF-mimicking disease, were not included. The gene discussed is SPP1; the disease is rheumatoid arthritis.