cAMP‐induced hFTOs to hMTOs transition recapitulated human thyroid development ex vivo. A) Heatmap of differentially expressed genes (DEGs; log2fold changes ≥ 0.3, p‐value ≤ 0.005) between hFTOs and hMTOs. Three independent experiments were sequenced for each stage. Genes associated with hormone generation were marked out highlighting upregulation of TPO, TG, TSHR, SLC5A5, IYD, and DIO2 in hMTOs. B) GSEA analysis showing enrichment of thyroid hormone synthesis pathway in hMTOs versus hFTOs. C) Heatmap of reported thyroid hormone related genes in hFTOs and hMTOs. D) Heatmap of reported cAMP related genes in hFTOs and hMTOs. E) Heatmap of different stages samples between biological replicates of Adult_Tissues (n = 2), Fetal_Tissues (n = 4), hFTOs (n = 3), and hMTOs (n = 3). And the main KEGG‐enriched terms of clusters 1–5 are shown on the right. The color from blue to red indicates the relative expression levels from low to high.