Tumour immunotherapy, such as treatment with immune checkpoint blockade (ICB), has revolutionised the approach to dealing with tumours and has significantly improved long-term survival rates.2 Currently, immune checkpoint inhibitors (ICIs) have made significant advancements in anti-tumour clinical applications, representing a breakthrough in the field of tumour therapy.3 Some of the well-established ICIs include cytotoxic T lymphocyte-associated protein 4 (CTLA-4), programmed death 1 (PD-1) and programmed death-ligand 1 (PD-L1). The gene discussed is CTLA4; the disease is neoplasm.