Circulating FABP4 levels correlate positively with BMI and indicators of metabolic syndrome in humans, and they are increased in mice with dietary or genetic obesity (10, 13, 16, 17), raising the possibility that excessive adipose tissue release of FABP4 may, in fact, be the strong contributor to metabolic dysregulation seen in mouse models and humans (18). This evidence concerns the gene FABP4 and metabolic syndrome.