Most findings have implicated novel genes or regions and suggested new mechanisms. For example, SNPs in FTO (“fat mass and obesity associated” gene) are strongly associated with common obesity. (49, 50) This was surprising, because FTO knockout mice are not obese. Mechanisms are under study, including a role in adipocyte lipolysis.(51) As Todd has noted (52), implicating a gene in disease requires both compelling statistical evidence for association and substantial additional biological evidence.
