CD274 and sarcoma: Although the expression of PD-L1 has been reported to be present in between 47–86% of paediatric sarcoma subtypes [20], there is significant variability in reported PD-L1 expression levels within different sarcoma subtypes, in the disease stage of sampling, the PD-L1 antibody clone used, the methods of tissue preservation employed, the subjective interpretation of immunohistochemical results, and the limited sample size [21,22,23].