A retrospective study conducted in ED-SCLC and LD-SCLC patients treated with a multimodal approach, including surgery for early stage, showed an association between CD8+ tumor infiltrating lymphocytes (TILs) and PD-L1 expression on tumor cells, whereas FOXP3+ infiltrate showed a positive correlation with PD-L1 positive tumor-infiltrating T cells [48]. This evidence concerns the gene CD274 and small cell lung carcinoma.