['Abdominal aortic aneurysms (AAA) are usually asymptomatic and mostly diagnosed incidentally. Aortic dilatation progresses along with the wall weakening and eventually leads to a life-threatening rupture. Currently, there are no effective screening biomarkers for AAA. MicroRNAs, a class of small non-coding RNA molecules, offer great potential as biomarkers because of their stability in the bloodstream and expression characteristic for different diseases.', 'To assess the circulating miR-29c-3p as a potential biomarker of AAA and to elucidate the biological functions of miR-29c-3p in terms of pathogenesis of aneurysms.', 'Two groups of patients scheduled for elective surgery were studied: 52 patients with AAA, and 51 patients with peripheral artery disease who served as a control group (matched by age and gender). Serum miRNA was measured for circulating miR-29c-3p using quantitative real-time PCR. Using in vitro culture of endothelial cells functional tests of miR-29c-3p impact on the targeted transcripts was done using its mimic or inhibitor Results: Serum miR-29c-3p was significantly elevated in AAA patients as compared with controls (RQ=8.73) and correlated with the diameter of the aneurysm. No association between well-known risk factors and level of circulating miR-29c-3p was found using a logistic regression. In vitro study revealed that miR-29c-3p suppresses transcripts of ELN, COL4A1, PTEN and VEGFA.'] Is miR-29c-3p an effective biomarker of abdominal aortic aneurysm in patients undergoing elective surgery?