CD4 and cancer: With the discovery that transforming growth factor-β (TGF-β) inhibits T helper cell (Th2)-mediated cancer immunity, researchers constructed a bispecific antibody targeting CD4 and TGF-β, 4T-Trap, which selectively inhibits TGF-β signaling by CD4+ T cells in lymph nodes (120, 121), leading to cancer cell apoptosis and vascular rearrangement.