STAT4 and major depressive disorder: In a study by Huang K et al. (23), utilizing the WGCNA approach, it was discovered that STAT4, CX3CR1, COL1A2, and SH2D1B, with STAT4 and COL1A2 being significant mechanisms implicated in the co-morbidities of heart failure and depression, offer new targets for investigating the pathogenesis of heart failure and depression, as well as for treating these conditions.