Mutations in at least 14 different genes (HNF4A, GCK, HNF1A, PDX1, HNF1B, NEUROD1, KLF11, CEL, PAX4, INS, BLK, ABCC8, KCNJ11 and APPL1) have been shown to cause MODY subtypes 1–14 (1–3). This evidence concerns the gene HNF4A and MODY.