Generation of hMGEOs and hCOs(A) Schematic view of the methods for generating hMGEOs and hCOs from hPSCs.(B) Induction of NKX2-1-GFP in hMGEO and hCO culture systems at different developmentalstages. Scale bar, 125 μm.(C-E) Immunostaining and quantification of GFP, FOXG1, and PAX6 in dissociated culture ofhMGEOs and hCOs (day 21). Mean ± SD for hMGEOs (n=10) and hCOs (n=9) are shown. Scalebar, 25 μm.(F) Typical interior cellular organization of hMGEOs (3 week old) and hCOs (4 week old). Scale bar,20 μm.(G) Morphology and size of hMGEOs and hCOs after 30 days and 70 days of culture. Scale bar, 4mm.See also Figure S1.