MMP9 and major depressive disorder: As shown in Figures 12C–F, the expression of co-hub genes ANGPT2 (AUC = 0.582, Figure 12C), MMP9 (AUC = 0.600, Figure 12D), PLAU (AUC = 0.602, Figure 12E), and TIMP2 (AUC = 0.685, Figure 12F) all had low accuracy in diagnosing MDD in the GSE98793 dataset.