Protein kinase C delta (PKC delta) is a member of the protein kinase C (PKC) family of serine-threonine kinases. It is a 79 kd protein kinase that shows strict dependence on the presence of phospholipids, but shows no activation by Ca2+ (1). Phosphatidylinositol is the most potent activator of PKC delta. Apparent kinetic constants for synthetic oligopeptides (MBP4-14, EGFR peptide and epsilon-peptide) are quite different between PKC delta and other PKCs. Northern blot analysis indicated that PKC delta is widely distributed in almost all the tissues and is a major isoform of PKC expressed in hemopoietic cells (2). PKC delta is involved in fundamental cellular functions regulated by diacylglycerols and mimicked by phorbol esters. PKC delta is