CCK and hereditary elliptocytosis: The gene expression levels of liver kinase B1 (LKB1), neuropeptide Y (NPY), cholecystokinin (CCK), fatty acid synthase (FAS), and glucocorticoid receptor (GR) in the hypothalamus of the 21-d-old broilers in the HE group were significantly downregulated compared with those in the control group (P < 0.05, Fig. 1).