CD274 and adenocarcinoma: The literature contains conflicting data on the association between NSCLC histology and PD-L1 expression, with some reports finding no significant differences,[19] while others report higher expression in adenocarcinoma,[8,20] or higher expression in squamous cell carcinoma.[10,16] In the present study, PD-L1 expression was more frequently observed in squamous cell carcinomas than in adenocarcinomas, particularly in the TPS ≥ 50% subgroup.