CD274 and neoplasm: It has been suggested that PD-L1 expression, mutational burden, and mismatch repair deficiency in tumors represent predictive biomarkers for clinical outcome of ICI therapy.8–13 Other explored biomarkers are related to tumor-infiltrating immune cells such as T cells (in their different phenotypic states),14 immunosuppressive macrophages and myeloid derived suppressor cells (MDSCs).15 16 However, despite intensive efforts in this direction, biomarkers available today for guiding clinical decisions are suboptimal in terms of their predictive value.17