CTLA4 and neoplasm: As anticipated, upon encountering tumor antigens, the tumor-specific CTLs in conjunction with LPS-RGD-Nb36-DOX were able to quickly blockade the CTLA-4/B7 axis, as seen by increased expression of CD25, CD69, and CD62L as well as increased cytokine secretion (TNF-α, IFN-γ, and IL-2).