In order to understand whether CTLA4 is expressed in NSCLC, whether tumour cell‐intrinsic CTLA4 plays a role in tumorigenesis, we examined the CTLA4, PD‐1, PD‐L1 expression levels in multiple NSCLC cell lines with different oncogenic mutations and in the tissue samples from NSCLC patients. This evidence concerns the gene PDCD1 and non-small cell lung carcinoma.