Therefore, AKT integrates various upstream inputs and triggers downstream network activities [17].While PTEN mutations are relatively uncommon in breast cancer (< 5%), PTEN protein loss is frequent (~ 30%) [12, 22].This loss is reported to be caused by various mechanisms, such as promoter methylation, loss of heterozygosity, and regulation at the RNA or protein level. This evidence concerns the gene AKT1 and breast cancer.