A study in human formalin-fixed paraffin-embedded brain tissues demonstrated that the miR-138-5p had significantly higher expression in fatal traumatic brain injury cases compared to cardiovascular controls [Bonin et al. DOI:10.3390/ijms241310836]. In a separate investigation of human serum exosomes, the miR-138-5p was found to be upregulated in sepsis compared to septic shock [Li et al. DOI:10.1038/s41598-025-89946-6]. Separately, a study in mice identified the miR-138-5p as one of 45 known miRNAs significantly regulated in the nucleus accumbens following chronic methamphetamine exposure, indicating its role in the molecular response to this drug of abuse [Zhu et al. DOI:10.002/jnr.23605].