AuNPs have been shown to play an anti-inflammatory role in mouse obesity, rat arthritis, and rat focal cerebral ischemia–reperfusion [8–11], and AuNPs can inhibit innate immune activation in macrophages in vitro by attenuating nuclear factor kappa beta (NF-κB), interferon-β/signal transducer and activator of transcription 1 (STAT1), and Toll-like receptor 9 signaling pathways [12–14]. Here, STAT1 is linked to obesity due to melanocortin 4 receptor deficiency.