When the AMPK and the mTOR pathway associated with mitochondrial metabolism are activated, their downstream PGC1α and T-box expressed in T cells (T-bet) are induced to up-regulate, which activates FAO and OXPHOS and promotes mitochondrial expansion in tumor-reactive CTLs, finally enhancing activation and proliferation of CTLs (Table 1). The gene discussed is MTOR; the disease is neoplasm.