MMP2 and depressive symptom measurement: Next, the downstream target genes of miR-29b-3p were predicted in the Targetscan database (http://www.targetscan.org/vert_71/) and miRTarBase (http://mirtarbase.cuhk.edu.cn/php/search.php) to obtain the intersections, and eventually 15 target genes were observed (Figure 5(f)), among which MMP2 was highly expressed in depression patients and correlated with microglia activation [17,18].