CD4 and malignant peripheral nerve sheath tumor: Of the two MPNST samples obtained at the same time from within the same tumor 12 years after original diagnosis (see Supplementary Figure 6), the low-grade sample exhibited much higher CD8+, CD4+, FOXP3+, CD45RO+, and CD56+ lymphocytic infiltrates than did the high-grade MPNST sample (Figure 4D).