Levels of TGF-β1 correlate with VO2peak, BMI, fat mass, adiposity, insulin resistance, and other metabolic disorders in humans (12) and is a negative regulator of metabolic adaptation to exercise training by inhibiting insulin signaling, mitochondrial activation, and enzymes involved in optimal metabolic adaptations in response to training (57). The gene discussed is TGFB1; the disease is Insulin resistance.