Dynamic changes of PD-L1 protein expression were observed in 4 RMS tumors evaluated at diagnoses/first progression of disease and at a (second) tumor progression post-treatment, suggesting that damages induced by chemotherapy treatments in tumor cells and stroma may foster an inflammatory microenvironment and recruitment of PD-L1 expressing immune cells, creating an immune contexture possibly druggable by immune checkpoint inhibitors. The gene discussed is CD274; the disease is neoplasm.