Cytotoxic T-lymphocyte antigen 4 (CTLA-4), PD-1 and its ligand (PD-L1), and lymphocyte-activation gene 3 (LAG3) are expressed at higher levels in tumour-infiltrating lymphocytes, in the stroma and in the invasive front of MMRd tumours than in MMRp tumours (Fig. 1, green panel) [45]. The gene discussed is CTLA4; the disease is neoplasm.