AKT1 and breast cancer: AKT1, AKT2 and AKT3 are the isoforms that have been identified so far and, although being found broadly expressed in the human body, they exert different and critical roles in cancer: for example, while AKT2 expression has been observed to increase in pancreatic cancer with a major role in cell migration and invasion, AKT3 expression was found increased in prostate and breast cancer [36].