PPARG and type 2 diabetes mellitus: Similar to studies of obesity, investigations of the genetic variation-underlying risk of T2D in African-Americans yield results that often support the existence of conserved biological pathways (e.g., PPARG), potentially important effects of population-level variation or selection in exerting opposing effects (e.g., ADAMTS2), as well as the contribution of study design (including sample size, adjustment for admixture, or use of ancestry-informative markers) to such findings.