Others have suggested that patients with breast tumours displaying aberrant PI3K/Akt/mTOR signalling will benefit the most from rapamycin-based therapies, because tumour cells that have abnormal expression in the PI3K/Akt/mTOR pathway may depend on this pathway for growth, and therefore may be sensitive to mTOR inhibitors (Hidalgo and Rowinsky, 2000; Carraway and Hidalgo, 2004; Thomas, 2006). This evidence concerns the gene MTOR and breast neoplasm.