Furthermore, a study by Ozcan and colleagues revealed an obesity-dependent increase in endoplasmic reticulum (ER) stress within hypothalamic neurons, and found that tunicamycin-induced ER stress in the brains of lean mice was sufficient to block hypothalamic STAT3 phosphorylation, following IP leptin administration (Ozcan et al. 2009). The gene discussed is LEP; the disease is Obesity.