['Carbohydrate antigen 125 (CA-125) is a glycoprotein produced by epithelial and mesothelial cells. Serum CA-125 can be elevated in many benign and malignant conditions in which these tissues are involved.', 'We measured serum CA-125 concentration in 112 patients with chronic lymphocytic leukemia (CLL) and evaluated their association with Binet stage, serum lactate dehydrogenase (LDH), beta2-microglobulin (β2-MG), CD38, 70-kDa zeta-associated protein (ZAP-70), immunoglobulin heavy-chain variable region (IGHV) mutated status and cytogenetic abnormalities.', 'The high level of CA-125 was associated with advanced Binet stage (r=0.463, p< 0.001), high level of LDH (r=0.404, p< 0.001) and β2-MG (r=0.274, p=0.004), and unmutated IGHV status (r=0.366, p=0.009). Multivariate analysis showed that advanced Binet (p<0.001) and unmutated IGHV status (p=0.018) were risk factors for the high CA-125 level. In univariate analysis, treatment-free survival (TFS) and overall survival (OS) were affected by Binet stage (p<0.001 and p=0.042, respectively), LDH (p=0.018 and p=0.013, respectively), β2-MG (p=0.006, TFS only), ZAP-70 (p=0.031, OS only), CD38 (p=0.003, OS only), the presence of del(17p13) or del(11q22.3) (p=0.006 and p=0.049, respectively), IGHV mutation status (p=0.018 and p< 0.001, respectively) and CA-125 (p=0.003 and p=0.034, respectively). In multivariate analysis, only advance Binet stage (p<0.001) was independent risk factor of shorter TFS. CD38-positive (p=0.020) and unmutated IGHV status (p=0.034) were independent risk factors of worse OS.'] Is serum carbohydrate antigen 125 an independent prognostic factor in patients with chronic lymphocytic leukemia?