High-resolution computed tomography scans on prone position of a worker with no history of smoking, who had been employed at an indium tin oxide target production facility for 7 years (sintering room for 4 years and indium oxide powder room for 3 years). The image shows subpleural interlobular interstitial thickening in both lower lung fields (arrows). The patient had no history of respiratory diseases. Results of health examinations were as follows: serum indium, 50 μg/L; KL-6, 1769 U/mL; FVC, 86% predicted; FEV1/FVC, 109.6% predicted.