Importantly, our earlier studies show that orexin injection stimulates SPA and associated non-exercise activity thermogenesis (NEAT) with a sustained promotion of total energy expenditure (TEE) [19], and orexin neuron activation increases NEAT, reduces obesity [20,21] and decreases body weight gain in animals [22,23]. The gene discussed is HCRT; the disease is obesity due to melanocortin 4 receptor deficiency.