Although Pln mutations either resulting in elevated PLN expression (Minamisawa et al., 2003) or reduced PLN phosphorylation (Schmitt et al., 2003; Haghighi et al., 2006) have been causally linked to human cardiomyopathy, it is unknown whether these mutations can affect skeletal muscle health. The gene discussed is PLN; the disease is cardiomyopathy.