Myo18b has been implicated in sarcomere assembly and maintenance of myofibril structure38 as well as human skeletal and cardiomyopathies when mutated.39,40 In addition, a polymorphism in Sez6l has been associated with ischemic heart disease in humans41 and five SNPs in Sez6l are significantly associated with the LVD trait. The gene discussed is SEZ6L; the disease is cardiomyopathy.