Exosomal miR-181a secreted by pediatric acute lymphoblastic leukemia (PALL) cells can promote cancer development by upregulating proliferation genes and downregulating apoptosis genes, and silencing this gene can inhibit cancer cell proliferation (30).Silencing TGF-β1 in leukemia-derived exosomes can promote CD4+ T cell proliferation and Th1 cytokine secretion, thereby stimulating specific cytotoxic lymphocytes and NK cytotoxicity more effectively and enhancing antileukemic immunity (93, 94). The gene discussed is CD4; the disease is cancer.