CTSB and idiopathic pulmonary fibrosis: In the univariate logistic regression for overall cohorts (n = 178), age (OR = 0.94, 95% CI 0.90–0.98, p = 0.006), BMI (OR = 0.89, 95% CI 0.81–0.99, p = 0.024), baseline FVC (OR = 0.96, 95% CI 0.94–0.98, p < 0.001), and CTSB level (ng/mL) (OR = 2.57, 95% CI 1.95–3.38, p < 0.001) were significantly associated with progressive IPF (Figure 5A).