Subsequent studies confirmed that in leukemia cell derived exosomes, silencing exosomal TGF-β1, which reduces the level of immunogenicity, can promote CD4+ T cell proliferation and Th1 cytokine (IFN-γ and IL-2) secretion, effectively stimulating the CTL response and the cytotoxicity of NK cells [34]. The gene discussed is TGFB1; the disease is leukemia.