Supplementation with vitamin D3 decreased the production of proinflammatory cytokines: TNFα, PAI-1 (plasminogen activator inhibitor-1), IL-6, and ROS and pro-fibrotic genes in studies on AT biopsies from patients with obesity and 25(OH)D insufficiency [127]. The gene discussed is IL6; the disease is obesity due to melanocortin 4 receptor deficiency.