GHSR and Hypoglycemia: Also, ghrelin-overexpressing, ghrelin-knockout, GHSR-knockout, GHSR-null and GOAT-knockout mice all demonstrate alterations in glucose homeostasis, with the most extreme phenotype—namely marked hypoglycemia and near death—appearing upon severe caloric restriction of mice with genetic deletion of either GOAT or ghrelin (Zhao et al., 2010a; Li et al., 2012).