One candidate gene not previously identified in human GWA studies is mitochondrial gene PARL, located at 3q27 with a documented functional, but controversial role in the development of T2D (Walder et al., 2005; Fawcett et al., 2006; Powell et al., 2008; Hatunic et al., 2009; Tang et al., 2009; Civitarese et al., 2010). Here, PARL is linked to type 2 diabetes mellitus.