To address this issue, we determined the Ct values of HPRT (both HPRT-ABI and HPRT-CCM) and CDKN1B by direct real-time RT-PCR in each 5 explanted donor and terminally failing DCM hearts, from which enough tissue amounts were accessible to adjust RNA to 50 ng/μl before cDNA synthesis. Here, CDKN1B is linked to familial dilated cardiomyopathy.