<正>Objective The observe the expression levels of PD-1/PD-L1 costimulatory molecules and explore the clinical significance in patients with chronic lymphocytic leukemia(CLL).Methods The expression of PD-1/PD-L1 in peripheral blood CD8+T cells,CD4+T cells,CD19+B,and dendrites cells(DC)was detected by flow cytometry in 57 CLL patients and 20 healthy controls.The correla-