Morbidly obese individuals represent one of the fastest growing subpopulations of obese individuals. Thus, it is of significant interest to broaden our understanding of the potential genetic causes of this public health concern. A recent study investigated a role of positional candidate gene GAD2 (the gene for glutamic acid decarboxylase) in the development of morbid obesity. This commentary carefully examines the genetic and functional arguments for and against the GAD2 gene as an influential gene for obesity. Also discussed are additional research questions that merit inquiry when further evaluating this genetic variant as a putative contributor to human obesity. © 2005 International Life Sciences Institute.