CD4 and neoplasm: Tumor infiltrate was very significant in GL261-CIITA tumors as compared to GL261 parental tumors and was mostly represented by CD3+ T lymphocytes, both CD4+ and CD8+ T cells (CD4+: 1,415 cells/mm2, CD8+: 989 cells/mm2 in GL261-CIITA; CD4+: 138 cells/mm2, CD8+: 72 cells/mm2 in GL261).