SOCS2 and major depressive disorder: In addition, in a mouse model of depression, Xian et al. found that neuron-derived EVs are rich in miRNA-9-5p, which can activate microglia by inhibiting suppressors of cytokine signaling 2 (SOCS2) expression and activating the JAK/STAT3 pathway to promote the release of inflammatory factors, thus exacerbating cognitive and behavioral disorders in mice (Xian et al., 2022).