FTO
A very thorough paper in PLoS Genetics on the "obesity gene," FTO, A Mouse Model for the Metabolic Effects of the Human Fat Mass and Obesity Associated FTO Gene:
Geneticists have identified many gene regions that cause human disease by using multiple genetic markers in large populations to find gene regions associated with disease. However, it is often not clear precisely which gene in any given region causes the disease or how the gene exerts its functional effect. For example, a gene variant in the non-coding region of FTO enhances obesity risk, but it is not clear if this is an effect of…