CAMK2G and angina pectoris: In patients with myocardial infarction and angina, increased protein phosphatase 1 (PP1) and reduced endogenous PP1 inhibitory protein inhibitor-1 (I-1) were associated with reduced CaMKII activity via dephosphorylation of the autophosphorylation site Thr287 of CaMKIIδ, while I-1 KO mice also showed reduced CaMKIIδ activity in the heart [101, 152].