The aim of this study was to serially analyze KL-6 in IPF patients after 24 months of Nintedanib and to investigate its biomarker potential in patients with IPF and lung cancer with respect to fibrotic hypersensitivity pneumonitis, pulmonary fibrosis associated with autoimmune diseases patients and healthy controls. The gene discussed is MUC1; the disease is hypersensitivity pneumonitis.