G? 6983 inhibits several isoforms of protein kinase C (PKC; IC50 = 7, 7, 6, 10, 60, and 20,000 nM for PKCα, PKCβ, PKCγ, PKCδ, PKCζ, and PKCμ, respectively). It provides cardioprotective effects in myocardial ischemia/reperfusion by attenuating contractile dysfunction.