Akt (also known as protein kinase B alpha) is a 60 kD serine/threonine specific kinase containing a pleckstrin domain. This kinase is ubiquitously expressed and translocates to the membrane upon activation. Akt phosphorylates substrates in both the cytoplasm and the nucleus. Akt exists as a catalytically inactive multimeric complex until phosphatidyl-3,4,5-triphosphate (PIP3) is generated as a result of cell signaling. Elevated PIP3 results in the partial activation of Akt after phosphorylation by phosphoinositide-dependent protein kinase 1 complex; Akt becomes fully activated only after autophosphorylation. Akt is a potent inhibitor of apoptosis and has been implicated as a factor in tumorigenesis and progression. Survival factors that suppress apoptosis activate Akt which phosphorylates and inactivates components of the apoptotic machinery. Akt can also be activated by TNF, IL-1, PDGF, and insulin like growth factor 1. Akt interacts through its pleckstrin homology domain with the second messengers phosphatidylinositol-(3,4,5)-trisphosphate (PtdIns(3,4,5)P[3]) and PtdIns(3,4). Akt has also been shown to interact with PED/PEA, TCL-1, Nur77, inosine-5'-monophosphate dehydrogenase, and PKC-zeta. The Poly6034 antibody has been shown to be useful for Western blotting of human Akt.