A review of human studies identified hsa-miR-221-3p as a biomarker downregulated in burn hypertrophic scar tissue compared to normal skin [Siu et al. DOI:10.1111/wrr.13100]. A study in humans demonstrated that the miR-221-3p is altered in the cerebrospinal fluid and saliva of pediatric traumatic brain injury patients [Li et al. DOI:10.1016/j.neuint.2023.105643].