CAMK2G and cardiomyopathy: Although acute sympathetic stimulation and activation of the cAMP-PKA pathway play a major role in improving cardiac function, previous studies using transgenic models have demonstrated that chronic sympathetic overactivity caused by the cardio-specific overexpression of β-AR [40, 41], Gsα [42], PKA [43] or CaMKII [44] resulted in cardiomyopathy.