Several studies have confirmed that EGFR mutations in NSCLC are closely related to an immunosuppressive tumour microenvironment (TME) (9–13) and a lower tumour mutation burden (TMB) (10, 14, 15), which are responsible for an inferior response to PD-1 blockade in NSCLC. The gene discussed is PDCD1; the disease is non-small cell lung carcinoma.