In fact, irradiation-induced upregulation of PD-L1 expression by various cell types within the tumor microenvironment has been described and radiotherapy in combination with anti-PD-L1 treatment was shown to act in concert in normalizing the immunosuppressive tumor milieu, thus highlighting the biological significance of PD-L1 upregulation in the tumor microenvironment in response to irradiation44. This evidence concerns the gene CD274 and neoplasm.