IFIH1 and interstitial lung disease: Among patients with anti‐MDA5 antibody (Ab) with RP‐ILD, the SF level (1531.0 [1163.8, 2016.5] vs. 584.9 [564.8, 1042.5], Z = 2.664, p = .008), γ‐GT (134.0 [81.0, 204.5] vs. 123.0 [76.0, 189.0], Z = 3.136, p = .002) and positive rate of anti‐RO‐52 Ab (90.9% vs. 50.0%, χ2 = 7.222, p = .013) were higher and lymphocyte count (0.79 ± 0.38 vs. 1.32 ± 0.74, t = −3.025, p = .029) was lower than those in their counterparts without RP‐ILD.