Indeed, obese individuals have been observed to have lower serum Metrnl levels [28], further reinforcing the underlying mechanistic basis of exercise being able to improve quality of life among CAD patients via increasing Metrnl production, leading to increased fatty acid and glucose metabolism, via activating pro-metabolic signaling pathways mediated by AMPK and PPARδ [18]. The gene discussed is PPARD; the disease is coronary artery disorder.