In addition, the deficiency of peroxisome proliferator-activated receptor γ coactivator-1 (PGC1α) in multiple cancers (e.g., colon and breast cancer) impairs mitochondrial biogenesis in the infiltrating T cells, leading to mitochondrial dysfunction and reduced T cell-mediated cytotoxicity (40, 44). Here, PPARGC1A is linked to breast carcinoma.