SFTPD and idiopathic pulmonary fibrosis: Although radiological findings on high-resolution computed tomography (HRCT) has been reported [3, 6], there is only limited information on the relevant biomarkers, such as surfactant protein D (SP-D) and Krebs von den Lungen-6 Antigen/MUC1 (KL-6/MUC1) in early stages of IPF [4].