AbstractBackgroundGalectin‐9 and myeloid‐derived suppressor cells (MDSCs) have an important role in tumors, but their clinical values in chronic lymphocytic leukemia (CLL) have not been fully elucidated. This study aimed to analyze the prognosis values of Galectin‐9 and MDSCs in CLL.MethodsThe concentrations of Galectin‐9, argininase‐1, and inducible nitric oxide synthase in serum were detected by enzyme‐linked immune sorbent assay. The expression of Tim‐3 protein in peripheral blood mononuclear cell was detected by Western blot. Flow cytometry was used to analyze the percentages of Tim‐3 on T‐cells (CD3+T, CD4+T, and CD8+T cells) and MDSCs.ResultsOur results showed that Galectin‐9 and MDSCs significantly increased in CLL patients and were closely related to the disease progression. Patient's receiver operating characteristic, progression‐free survival, and Cox regression analysis showed that Galectin9 and MDSCs were poor prognostic factors of CLL.ConclusionGalectin‐9 and MDSCs were associated with clinical progression and could be important prognostic indicators for CLL.