SIRT1 and familial dilated cardiomyopathy: Several upstream signals of abnormal mitochondrial dynamics have been described in the setting of DCM, including translocase of outer mitochondrial membrane 70 (Tom70) 121, cyclin C 122, sirtuin 1 (Sirt1) 123, estrogen 124, Gp78 125, insulin 126 and norepinephrine 127.