https://www.selleckchem.com/products/cynarin.html 5% showed normal levels in AFP and 68.8% showed normal levels in PIVKA-II. In 36.4% of those patients, both AFP and PIVKA-II showed normal levels. The PIVKA-II-positive ratio was markedly increased with an increase in the tumor size. In contrast, the positivity in AFP was increased gradually and slowly. In the surveillance of very small HCC nodules (≤ 2 cm in diameter, Barcelona clinical stage 0) the tumor markers AFP and PIVKA-II are not so useful. In the surveillance of very small HCC nodules (≤ 2 cm in diameter, Barcelona clinical stage 0) the tumor markers AFP and PIVKA-II are not so useful. MicroRNAs (miRNAs) have been suggested as biomarkers for malignant diseases including hepatocellular carcinoma (HCC). Specifically, hsa-miR-21-5p (miR-21) is among the most frequently deregulated miRNA in cancer. The diagnostic and prognostic value of miR-21 has been demonstrated in HCC tissue, mostly in the Asian population. Although the impact of various factors has been recently reported for circulating hsa-miR-122-5p (miR-122), at present only limited knowledge is available for miR-21. To evaluate the value of miR-21 for the assessment of prognosis in HCC patients and to delineate the influence of clinical and preanalytical factors on miR-21 level in sera. Patients with confirmed HCC from our European cohort with predominantly alcohol-associated liver damage were included in the study. All subjects were characterized according to their clinical and laboratory work-up and overall survival data were obtained. Quantitative real-time polymerase chain reaction was performed for miR-21 and spiked-in cel-mase as potential factors that may affect miR-21 concentration in blood. This knowledge should be considered in future miRNA-based biomarker studies not only for HCC but also for other diseases. The results from this work do not support clinically relevant prognostic value of circulating miR-21 in HCC patients in real-life setti