CD274 and squamous cell carcinoma: The study found that compared with adenocarcinoma, the expression of PD-L1 in squamous cell carcinoma is more common, and the infiltration of macrophages and other immune cells is more prominent, which brings an opportunity for the treatment of patients with advanced squamous cell carcinoma, and also leads to the different response of squamous cell carcinoma and nonsquamous cell carcinoma to immunotherapy (26).