Objective:To investigate the expression of Toll-like receptors 2(TLR2) in peripheral blood mononuclear cells(PBMCs)from patients with ovarian cancer,and its role in inducing the expression of IL-10. Methods:We collected PBMCs from 20 patients with ovarian cancer, 20 with benign diseases and 20 healthy females. Expression levels of TLR2 mRNA in PBMCs in the 3 groups were determined by real-time quantitative PCR and then compared. PBMCs were then stimulated with TLR1,TLR2 and TLR6 ligands. The expression and secretion levels of IL-10 in each troup were assessed by real-time PCR and FACS,respectively. Results:TLR2 were all expressed in PBMCs of the three groups, and the expression levels of TLR2 mRNA in PBMCs in patients with ovarian cancer were higher than the benign group and the healthy controls(both P < 0.05). There was no significant difference in TLR2 between the benign group and the healthy controls. After stimulated with HKLM(TLR2 ligand) for 24 h,IL-10 mRNA level was significantly higher in the ovarian cancer group compared to those in the benign controls and the healthy controls(Fold = 2.25,P < 0.05;Fold = 2.33,P < 0.05). There was no significant difference in IL-10 mRNA level between the benign controls and the healthy controls. Increased expression of IL-10 was also observed upon stimulation by FSL-1(TLR6 ligand) in ovarian cancer patients compared to those in the benign controls and the healthy controls(Fold = 1.95,P < 0.05;Fold = 2.16,P < 0.05). No signifiant difference was found between the benign controls and the healthy controls. Furthermore,there was an observable increased(P < 0.05) IL-10 secretion level upon stimulation by TLR2 ligand HKLM for 24 h in ovarian cancer patients(Medium = 150.46) compared to the benign controls(Medium= 38.86 pg/ml)and the healthy controls(Medium = 44.93 pg/ml),while no significant difference was identified between the benign group and the healthy controls. It was particularly noteworthy that PBMCs did not show significant up-regulation of IL-10 production in response to Pam3CSK4(TLR1 ligand) (M=46.70,61.53 and 31.11 pg/ml,respectively) and FSL-1 stimulation (M=20.20,31.12 and 35.45 pg/ml,respectively) in the 3 groups. Conclusion:TLR2 was highly expressed in PBMCs in ovarian cancer patients. IL-10 may be related to the immune evasion of ovarian cancer,which promotes the tumor progression by tumor immune escape.