CD274 and neuroendocrine carcinoma: The keyword clustering analysis identified 16 clusters, which included themes such as chemotherapy, tumor infiltrating lymphocytes, tumor microenvironment, cancer immunotherapy, non-small cell lung cancer, tumor suppressors, metastatic melanoma, dendritic cells, regulatory T cells, PD-1/PD-L1 inhibitors, lung cancer, immune checkpoint inhibitor, KRAS mutation, immune evasion, neuroendocrine carcinoma, and immune checkpoints.