CTLA4 and neoplasm: The frequencies of TNF‐α+IFN‐γ+ and CD69+ tumor‐infiltrating CD8+ T cells were increased by anti‐APOC2K70‐lac Ab or FX11 in LLC tumors (Figure S9E–G, Supporting Information), with decreased the frequencies of Treg cells (Figure 8F,G), resulting in a higher ratio of Treg cells: CD8+ T cells (Figure 8H) as well as increased expression of their active markers (CTLA‐4, GITR, LAG‐3, and OX‐40) in LLC tumors (Figure 8I,J).