HNF1B and diabetes mellitus: These include the 13 MODY genes (GCK, HNF1A, HNF4A, HNF1B, INS, NEUROD1, PDX1, PAX4, ABCC8, KCNJ11, KLF11, CEL, and BLK), 6 genes associated with recessive diseases that include diabetes as a phenotype (WFS1, NEUROG3, EIF2AK3, GLIS3, RFX6, and SLC19A2), and 3 genes in which heterozygous mutations have been shown to cause diabetes mellitus (PAX6, GATA6, and PPARG).