As the intermediate filament protein nestin is expressed in neural stem cells and reactive astrocytes (which are a feature of diet-induced obesity in mice) a contribution of changes in JNK1 signalling in astrocytes to the phenotype seen cannot be ruled out; particularly considering the importance of this signalling pathway in regulating astrogliosis (described above). This evidence concerns the gene NES and obesity due to melanocortin 4 receptor deficiency.