FOXA1 and diabetes insipidus: Hepatocyte nuclear factor 3 α, (HNF3A, also known as FOXA1), is a transcription factor in the forkhead box (Fox) family that functions in various pathological processes, and also functions in normal embryonic development, cell differentiation, cell proliferation, and apoptosis.[7, 8, 9, 10, 11, 12, 13] Mice deficient in Hnf3a can survive postnatally, but die after 2 to 12 days due to hypoglycemia and nephrogenic diabetes insipidus.[9, 13] HNF3α exhibits tissue‐specific expression in adult tissues, and primarily functions in the liver, pancreas, and prostate.