However, as earlier discussed, significant PD-L1 expression by the lymphoma cells, which might evidence tumour progression and more clearly associates with specific subtypes of DLBCL, may become a critical limiting factor for anti-PD-1/PD-L1 efficacy and requires further investigation as a predictive biomarker of immunotherapy responses in DLBCL. This evidence concerns the gene CD274 and diffuse large B-cell lymphoma.