A study in humans demonstrated that the miR-27a-5p is associated with traffic-related air pollution (TRAP) component exposure, specifically with PM10, PM2.5, black carbon, ultrafine particles, and NO2 in plasma [Kotsyfakis et al. DOI:10.1080/1354750X.2019.1652348]. A study in rats demonstrated that miR-27a-5p was significantly downregulated in the hippocampus following cardiac arrest and cardiopulmonary resuscitation, validating its role as a post-cardiac arrest brain injury biomarker [Li et al. DOI:10.1038/s41598-024-75875-3]. In humans, serum levels of miR-27a-5p were significantly decreased in patients with multiple organ dysfunction syndrome caused by acute paraquat poisoning, showing high diagnostic accuracy and serving as an independent prognostic factor for 30-day mortality [Dai et al. DOI:10.3892/Etm.2020.8409].