STING1 and obesity due to melanocortin 4 receptor deficiency: Current studies emphasize the cGAS–STING axis in DR-linked endothelial senescence but overlook cell-type-specific triggers (e.g., mitochondrial vs. nuclear DNA damage) and fail to address how obesity-linked inflammation in type 2 diabetes may synergistically amplify STING activation, a gap unmodeled by STZ-induced diabetic models.