In vitro information is available for HCM- and DCM-causing mutations in ACTC1. Furthermore, it has been studied in vivo with HCM-causing mutations in MYBPC3, MYH7, and MYOZ2; DCM-causing NEBL mutations; and RCM-causing TNNI3 mutations (Table 1). The gene discussed is ACTC1; the disease is familial dilated cardiomyopathy.