NF1 and central nervous system cancer: Similarly, whereas VLA-4 is required for CD8+ T cell infiltration into Nf1 optic gliomas, as revealed by the anti-VLA4 antibody experiments, differential VLA-4 expression in CD4+ versus CD8+ T cells does not account for the preferential CD8+ T cell infiltration in Nf1 murine optic gliomas28 and human NF154 gliomas (Supplementary Fig. 6g, h).