To determine whether the activation of the Akt/mTOR/p70S6K signalling pathway, which participates in tumours resistant to radiation therapy [28], was involved in the response of breast cancer cells to carbon ion irradiation, we tested the phosphorylation levels and total expression levels of the Akt/mTOR/p70S6K pathway 48 h after irradiation. This evidence concerns the gene AKT1 and breast cancer.