CD274 and breast cancer: Furthermore, Dai et al. proposed that the exposure of breast cancer cells to a ketogenic diet in a mouse model could induce the activation of AMP-activated protein kinase (AMPK), which may improve the efficacy of anti-CTLA-4 immunotherapy by reducing Programmed Cell Death Ligand 1 (PD-L1) expression and enhancing the expression of antigen-presenting genes and type-1 interferon (124).