CTLA4 and cancer: Despite the reinvigorated antitumoral immune response after Slc4a4 targeting, in the Panc02 model, expression of programmed cell death protein 1 (PD-1) in CD8+ T cells and cytotoxic T lymphocyte-associated protein 4 (CTLA-4) in Treg cells (considered the most representative cellular compartments for the expression of these immune checkpoints45) and programmed death ligand 1 (PD-L1) levels in cancer cells in vivo were still high and comparable in sgNT versus sgSlc4a4 Panc02 tumors (Fig. 8a–c, left, and Extended Data Fig. 8a).