The group of mice that received P14 lin28Tg CTLs with rapamycin/NAC treatment had reduced tumor growth which significantly prolonged mouse survival in comparison to the group with untreated P14 lin28Tg CTLs (Fig. 5j, Supplementary Fig. 9c), suggesting that inhibition of mTOR and ROS partially rescued the cytotoxic function of let-7 deficient CTLs in vivo. Here, MTOR is linked to neoplasm.