hsa-mir-4521: Hsa-mir-4521 is a microRNA that has been evaluated in patients with focal cortical dysplasia (FCD) and a control group, using temporal cortex tissue and serum samples [PMC7824581]. It has been suggested that hsa-mir-4521 may have an antiviral role during Newcastle disease virus (NDV) infection in HeLa cells [PMC8211993]. In the context of hypoxia, multiple miRNAs were found to be deregulated in different cell lines [PMC8202010]. In Caco-2 cells, five miRNAs (hsa-miR-27b-5p, hsa-miR-148a-3p, hsa-miR-200a-5p, hsa-miR-1260a, and hsa-miR-1260b) were affected [PMC8202010]. In HT-29 cells, four miRNAs (hsa-let-7a-3p, hsa-miR-22-3p, hsa-miR-615-3p, and hsa-mir-4521) were identified as being deregulated [PMC8202010]. In an experimental study using HeLa cells transfected with plasmids and miRNA mimics or inhibitors, the role of hsa-mir-4521 was investigated [PMC8211993]. Finally, a risk score formula was developed using multiple miRNAs including hsa-mir-501 and hsa-mir-5091 [PMC6089101]. Overall, these findings suggest that Hsa-mir-4521 may have various roles in different cellular contexts including antiviral activity during infection and potential involvement in disease risk assessment [PMC7824581][PMC8211993][PMC8202010][PMC6089101].