We utilized VOSviewer and CiteSpace for keyword analysis, resulting in the visualization map (Fig. 6A). The top 20 keywords identified included nivolumab, docetaxel, pembrolizumab, open-label, cellular lung cancer, chemotherapy, immunotherapy, non-small cell lung cancer, multicenter, PD-L1 expression, treatment, survival, blockade, atezolizumab, T-cells, death ligand 1, safety, ibritumomab, activation, and melanoma. Figure 6B showed the frequency distribution of these keywords, with nivolumab appearing most frequently at 342 occurrences (8%). This evidence concerns the gene CD274 and melanoma.