Akt, also referred to as PKB and RAC, is the cellular homologue of the viral oncogene v-Akt. This protein kinase is activated by insulin and various growth factors and functions in a pathway involving PI3 kinase as activation is sensitive to wortmanin. Recent evidence sμggests that Akt functions to promote cell survival by actively inhibiting apoptosis, althoμgh the pathways involved have not been identified. Akt is activated by phospholipid binding and phosphorylation within the activation loop at Thr308 and within the C-terminus at Ser473.