HAP1 and metabolic syndrome: In the present study, several genes related to the functional cluster of membrane proteins or receptors showed altered expression in ZDF hearts as compared to controls (e.g. down-regulation of ATPase, (Na+)/K+ transporting, beta 4 polypeptide; G protein-coupled receptor 37 and up-regulation of ATPase, H+/K+ transporting, nongastric, alpha polypeptide; Huntingtin-associated protein 1). Interestingly, here we have found gene expression changes of two members of the X,K-ATP-ase family due to metabolic syndrome.