A collection of genetic variants influences the expression of obesity-associated genes in both the brain and fat tissue, according to a new study from researchers at the University of Chicago. The research team found that changes in the expression of the obesity-associated genes correlated with both metabolic and behavioral changes, suggesting that these variants produce combinatorial effects that increase the risk of obesity. The results, which scientists hope will lead to better understanding of the mechanisms that make some people more susceptible to obesity, were published June 4 in Science.