Further, by maintaining and maturing iPSC-derived AT2 cells using SPC-GFP reporter or NaPi2B, an AT2 cell surface antigen, we established human iPSC-based disease models related to abnormalities in lamellar bodies caused by amiodarone, an antiarrhythmic agent notorious for inducing pulmonary fibrosis, and AP3B1 deficiency, which is observed in HPS2 patients [3, 20, 21]. This evidence concerns the gene AP3B1 and pulmonary fibrosis.