FGF2 and obesity due to melanocortin 4 receptor deficiency: Moreover, the acquisition of cocaine self-administration is increased by systemic recombinant FGF2 treatment [96], rodents selectively bred for a low novelty response have lower FGF2 in association with reduced addictive behaviors related to cocaine self-administration [97] and the disruption of FGF2 signaling enhances thermogenesis and protects against weight gain and the development of obesity [98].