The Akt cascade works through receptor tyrosine kinases, integrins, B and T cell receptors, cytokine receptors, G protein coupled receptors and other stimuli that induce the production of phosphatidylinositol 3,4,5 triphosphates (PtdIns(3,4,5)P3) by phosphoinositide 3-kinase (PI3K). There are three highly related isoforms of Akt (Akt1, Akt2, and Akt3), being the major signaling arm of PI3K.