(a) A flow cytometric analysis of PDPN and SFTPC expression in EPCAM+ gated cells of P0, P1, P2, P5 and P6 FD-AOs, respectively. The values indicate the percentage of each population, mean ± s.e.m (n = 3 independent organoids, each). (b) The ratio of PDPN+/- cells in FD-SFTPC+ cells in each passage. *P < 0.05, Kruskal-Wallis test combined with Dunn’s post hoc multiple comparison test. Error bars indicate the mean ± s.e.m (n = 3 independent organoids, each). (c) TEM images of isolated P2 FD-SFTPC+ cells. The cells were morphologically classified into the three following three types: “immature type”, cells with large glycogen vacuole-like structures without lamellar bodies; “early type”, cells with the glycogen vacuoles with small lamellar bodies; and “late type”, cell with small or no glycogen vacuoles with well-structured lamellar bodies (n = 3 repeated experiments). B2-3 hiPSC line was used for all of the experiments.