STING1 and obesity due to melanocortin 4 receptor deficiency: Cytosolic mtDNA stimulation of the cGAS-STING pathway was observed in adipocytes 28, the endothelium 29, 30 and cardiomyocytes 31, thereby regulating inflammation, macrophage infiltration, insulin resistance, atherosclerosis and obesity-induced diabetic cardiomyopathy.