Moreover, we provide evidence that CDKN1B (cyclin-dependent kinase inhibitor 1B) as well as HPRT (hypoxanthine-guanine phosphoribosyltransferase) is not differentially expressed in DCM versus donor hearts, and may therefore be a relevant housekeeping gene candidate for real-time RT-PCR analyses of myocardial tissues. Here, CDKN1B is linked to familial dilated cardiomyopathy.