Bearing in mind the wide range of PD-L1 expression reported in the literature (ranging between 0% and 97% in tumour cells and between 15% and 97% in immune cells) [34,35,36,37,38,41,42,43,44,47,48,49,51], our findings are supported by several series where PD-L1 expression was shown to be higher in immune cells than in tumour cells [34,36,37,39,42,43,47,48,49,51] (Supplementary Table S8). The gene discussed is CD274; the disease is neoplasm.