14-3-3 proteins (green) are primarily involved in the serine/threonine protein kinase Akt pathway and in the extracellular signal-related kinase pathway (ERK1/2). Akt is linked through phosphoinositide 3-kinase (PI3K) to cell surface receptors and inhibits apoptosis by phosphorylation of Bad. Phosphorylated Bad binds to 14-3-3, causing dissociation of the Bad/Bcl-xL complex and allowing cell survival. 14-3-3 proteins are also involved at several steps of the Raf1 signal transduction pathway, linking growth factor receptors with the regulation of gene expression and thereby highlighting the complex involvement of 14-3-3 proteins in the regulation of development, differentiation, cell cycle and cellular proliferation. JNK, Jun N-terminal kinase; MEK, MAP-kinase kinase; PKC, protein kinase C; PLC, phospholipase C.