Eukaryotic elongation factor 2 kinase (EEF2k) previously known as Ca2+/calmodulin dependent protein kinase III, is an abundant cytoplasmic protein highly specific for elongation factor 2 (eEf2). Phosphorylation of eEF2 by eEF2 kinase on specific threonine residues results in the inactivation of eEF-2 and in termination of mRNA translation. The activity of eEF2 kinase is not only dependent upon Ca2+ ions, calmodulin (CaM) and insulin, but is also regulated both negatively and positively via phosphorylation by different protein kinases (AMPK, S6K1, p90 RSK). There is also evidence that eEF-2 phosphorylation is involved in the regulation of cell cycle progression, cellular differentiation, oogensis and malignant tumors.