Protein kinase C (PKC) is a large superfamily of serine/threonine kinases that mediate essential cellular signals required for activation, proliferation, differentiation and survival. There are at least ten PKC isoforms that are closely related structurally but have different tissue distribution and functional patterns.PKC isoforms can be subdivided into three categories based on their primary structural and biochemical properties. These are: classical or conventional PKC isoforms (cPKC), novel PKC isoforms (nPKC) and atypical PKC isoforms (aPKC).