Left ventricular myocardial levels of the interleukins, IL-1b, IL-2, IL-6, and IL-8 were quantified by high sensitivity multiplex suspension array in both adult and paediatric dilated cardiomyopathy (DCM) samples. Detectable levels were obtained in both sample sets, but IL-1b, IL-2, and IL-8 were significantly increased in paediatric DCM. The distribution of absolute values, in femtograms/mg wet weight of myocardium (fg/mg) is shown along with the mean and standard error of the mean (SEM). *P < 0.05 vs. adult DCM.