Our previous work examining an array of DCM-causing mutations in TnT [ΔK210 (40) and R131W, R141W, A172S, R205L and D270N (26)], TnI [K36Q and N185K (6)], and α-TM [E40K and E54K (27) and D230N (22)] has shown a uniform reduction in the Ca2+ sensitivity of actin-activated myosin ATPase activation. Here, ATM is linked to familial dilated cardiomyopathy.