Our previous data of a reduced level of terminally differentiated CD8(+)/CD57(+) and CD27(−) T cell fractions in NF1 patients with high benign internal tumor load may indicate a reduced immune capacity already at the benign state, which is further exacerbated by the high PD L1 levels at the malignant state. This evidence concerns the gene CD27 and neurofibromatosis type 1.