Figure 1. Phosphorylation of the androgen receptor (AR) by MAPK and AKT. Numerous signalling factors (intracellular and extracellular), involved in inducing cell growth and proliferation, stimulate the Ras pathway to activate MAPK. Subsequently, MAPK phosphorylates AR, enabling AR to form dimers, enhancing ARE (androgen response element) dependent gene expression. Similarly, intra- and extra-cellular factors inducing cell growth and migration and inhibiting cell adhesion activate the PI3 kinase pathway resulting in AKT dependent phosphorylation, dimerisation and activation of AR.