Disruption of calcium handling is a common theme among cardiomyopathies (5) and drug-induced cardiotoxicity (6), with indication of decreased expression of RYR2 in some forms of human heart disease (7, 8) and animal models of heart failure (9–11), implicating RYR2 dysfunction as an element of heart disease or within predisposed conditions. This evidence concerns the gene RYR2 and cardiomyopathy.