MYD88 and obesity due to melanocortin 4 receptor deficiency: In this study, we investigated whether MyD88 signaling in astrocytes is involved in hypothalamic inflammation and reactive gliosis and whether altering the activity of MyD88 signaling in astrocytes, using mutant mice bearing an astrocyte-specific deletion of Myd88 gene expression, would affect the obesity phenotype and leptin resistance induced by HFD consumption.