A gene discovered by Rutgers researchers, Lipin, and its associated protein (PAP), seem to be key to fat regulation
. Lack of the gene causes a loss of body fat, and more of it causes excess body fat. Potential uses for this discovery are, besides the obvious weight-loss craze (I'll take a lifetime supply of Lipin-inhibitors please), in the facial wasting symptoms suffered by HIV/AIDS patients.
Another gene, which is related to aggressive behavior in men seems also to lead to weakened impulse control and increased alarm responses
. But, the men were only really more prone to violence if they'd been abused as children.