Kwong FNK, et al. - Experts comprehensively evaluated the immunohistochemical profile of tumours and sought to associate this with morphological tumour features in the case of non-small-cell lung carcinomas. Notable differences were illustrated in the programmed death-ligand 1 (PD-L1) expression in association with histological patterns, displaying high levels in those with pleomorphic features and low/undetectable levels in invasive mucinous adenocarcinomas and the lepidic components of non-mucinous adenocarcinomas. Hence, the PD-L1 expression analysis in a resected adenocarcinoma with a lepidic component did not appear to be reliable when immunomodulatory therapy for recurrent disease was taken into account. It was determined that re-biopsy or limiting assessment to the invasive component could be more appropriate.