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. The gene discussed is HPRT1; the disease is familial dilated cardiomyopathy.