CD274 and neoplasm: However considering that, mainly due to tumor immune-escape mechanisms exploited by cancer and/or tumor heterogeneity, some patients with high PD-L1 expression do not benefit from ICIs as well as some patients with a low or negative PD-L1 expression; hence, there is an urgent need to identify other sources of both biomarkers and novel biomarkers with the aim to improve the selection of patients eligible for immunotherapy.