Most critically, mTOR is involved in the transition of effector to memory CD8+ T cells (Figure 2), and this appears to rely on conversion of T-bet to eomesodermin transcription factor expression [24-26]; blocking mTOR with rapamycin has this exact effect, and therefore promotes the development and sustenance of memory T cells that transition efficiently into effector cells highly capable of producing immune responses to, for instance, tumours [24]. This evidence concerns the gene CD8A and neoplasm.