Metastasis in breast cancer significantly increases morbidity and mortality. The 5-year survival rate reduces from 90% for localised disease to about 20% once metastasis has taken place. The phosphoinositide 3-kinase/Akt signalling pathway has an important role in cell motility, invasion and metastasis. However, the precise contribution of the Akt kinase family members, Akt1, Akt2 and Akt3, in mediating these processes is unclear. The possibility that they have distinct functions in tumour progression is particularly interesting.