CD4 and neoplasm: However, it is likely that the depletion of the Foxp3+ CD4+ regulatory T cells, which suppresses CD8+ T cell expansion in the draining lymph node through the cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) medicated downregulation of B7 co-stimulatory molecules in DCs, may contribute to the increased number of tumor-infiltrating CD8+ T cells.