A recent study analyzing 528 samples of Han Chinese MDD patients from northern China demonstrated that the interaction effect between VEGF (rs699947, rs833061, rs2010963) and 5-HT1A (rs6295, rs1364043, rs878567) genes has a clear pathological correlation with MDD (CV consistency = 10/10, P = 0.0107) (Han et al., 2019). Here, HTR1A is linked to major depressive disorder.