['To investigate for the first time whether the plasma CXCL16 concentration is altered in coronary artery disease (CAD) patients.', 'Accumulating evidence suggests that the novel chemokine/scavenger receptor CXCL16/SR-PSOX is involved in the development of atherosclerosis and CAD.', 'Using ELISA we assessed the plasma CXCL16 concentration in 40 stable angina pectoris (SAP) patients, 17 unstable angina pectoris/non-ST-elevation myocardial infarction (UAP/non-STEMI) patients, 387 survivors of a first myocardial infarction (MI) and healthy control subjects (44 controls for SAP and UAP/non-STEMI patient groups and 387 controls for post-MI patients).', 'SAP patients exhibited significantly lower median CXCL16 levels (2111 pg/ml) than the corresponding control subjects (2678 pg/ml) (P=0.0012). UAP/non-STEMI patients also appeared to have lower CXCL16 levels (2192 pg/ml) compared with controls (NS). Patients investigated 3 months after MI tended (P=0.07) to have lower CXCL16 levels (2529 pg/ml) than the corresponding controls (2638 pg/ml). There were no significant correlations between CXCL16 levels and different measures of CAD severity determined by quantitative coronary angiography in post-MI patients. Neither patients nor controls exhibited significant correlations between CXCL16 levels and plasma lipoprotein fractions, inflammatory cytokines, C-reactive protein or numbers of inflammatory cells in peripheral blood.'] Is decreased plasma CXCL16/SR-PSOX concentration associated with coronary artery disease?