To assess tumors in the context of their microenvironment, we performed immunohistochemical staining for immunologic markers of interest (HLA-A/B/C, B2M, and PD-L1) on benign (histologies depicted in Supplementary Figure 2) and malignant tumors from NF1 patients and scored their staining intensity and percentage as previously described [17]. This evidence concerns the gene CD274 and neurofibromatosis type 1.