PPARγ has been widely studied because it is important in adipocyte and lipid metabolism.  In addition, it is a target for the hypoglycemic drugs known as thiazolidinediones.  One form the PPARγ gene (Pro12Ala – Pro is the risk allele) decreases insulin sensitivity and increases T2D risk by several fold.  Perhaps more important is that this variant is very common in most populations.  Approximately 98% of Europeans carry at least one copy of the Pro allele. Thus, it has been estimated that this variant contributes to about 25% of T2D that occurs in populations, particularly among Caucasians.  Additional information about this and other T2D genes can be found by searching the OMIM (Online Mendelian Inheritance in Man) database on the National Center for Biotechnology Information web site (www.ncbi.nlm.nih.gov).