Moreover, as described in our previous article, when PD-L1 expression was evaluated using three scoring methods, different studies, just like in this case, performed immunohistochemistry using several assays with diverse thresholds for positivity, variation of tumour sample size (biopsy vs. resection specimens), and localization (primary tumour vs. metastasis), which could also lead to controversial results [44,45]. This evidence concerns the gene CD274 and neoplasm.