An unadjusted comparison between IIM-ILD patients with or without RP-ILD showed that patients who later developed RP-ILD had more complications of pulmonary bacterial infection (P = 0.036) and gastrointestinal haemorrhage (P = 0.044), higher MYOACT score (P = 0.006), a higher bilateral lung SUVmean (P < 0.001, Fig. 2B), more abnormal mediastinal (P = 0.002) and hilar (P = 0.018) lymph nodes, lower total lung capacity (TLC, P = 0.049), lower percent-predicted diffusing capacity of the lung for carbon monoxide (DLCO%, P < 0.001, Fig. 2C) and positivity of anti-MDA5 antibody (P = 0.016). The gene discussed is IFIH1; the disease is interstitial lung disease.