TSLP and idiopathic pulmonary fibrosis: In the subgroup of IPF patients treated with nintedanib, IL-33 EBC follow-up levels did not differ significantly from baseline levels (1.47 (1.41–1.60) pg/mL vs. 1.44 (1.29–2.09) pg/mL, respectively) as well as TSLP EBC follow-up levels were not different from baseline levels (11.88 (10.00–13.75) pg/mL vs. 15.00 (12.50–15.00) pg/mL, respectively).