In the univariate analysis of baseline characteristics in category 3, prior RT or ICI therapy within 90 days before starting new cancer treatment (OR: 2.19, 95% CI 0.94–5.10; p = 0.069) and a high serum KL-6 level at baseline (> 302.4 U/mL) (OR: 2.62, 95% CI 1.02–6.73; p = 0.046) were associated with the development of severe TR-ILD (see Supplementary Fig. S3a online). The gene discussed is MUC1; the disease is cancer.