In PD-1/PD-L1 blocking therapy, tumour infiltration by cytotoxic T cells is critical for clinical success.41 In a successful anti-PD-1 antibody therapy on melanoma patients, CD8 + T cells infiltrated melanoma tumours.42 In a mouse ovarian tumour model, T-cell infiltration of tumours was induced in response to PD-L1 blocking therapy.43 Highly selective cytotoxicity of IF7C(RR)-SN38 to cancer cells may allow an intact inflammatory T-cell response to brain tumours. The gene discussed is CD8A; the disease is cancer.