After the intervention of IL-38, the expression of VEGF, VEGFR1 and VEGFR2 in CLL group slightly decreased (P<0.05 vs CIA), suggesting that IL-38 can inhibit the neovascularization of CIA rats by down-regulating the expression of VEGF, VEGFR1 and VEGFR2. The gene discussed is FLT1; the disease is B-cell chronic lymphocytic leukemia.