Researches have demonstrated that CD4+ CD25+ Foxp3+ Tregs inhibited proliferation, activation, degranulation, and production of granzyme A, granzyme B, and perforin of CD8+ T cells induced by anti-CD3/CD28 antibodies [21] and are potent suppressors of autologous tumor-specific T cell responses [47]. Here, CD28 is linked to neoplasm.