Previous reports have already associated exacerbation and prognosis of RA-ILD+ and SSc-ILD+ with MMPs, emphasizing MMP-7 (Chen et al. 2023; Chen and Chen 2020; Moinzadeh et al. 2011), MMP-9 (Lv et al. 2022; Luedders et al. 2024; Guiot et al. 2020) and MMP-12 (Manetti et al. 2012). The gene discussed is MMP9; the disease is systemic sclerosis.