Lymphocytes proportion was significantly associated with CpGLV in the TPH2 models including the healthy cohort (DASB: β: 0.017, p = 0.017, 95% CI: [0.004; 0.04]; SB: β: 0.016, p = 0.019, 95%CI: [0.003; 0.03]) and both in the SLC6A4 and TPH2 models based on the MDD patients cohort (SLC6A4: β: 0.014, p = 0.03, 95% CI: [0.002; 0.03]; TPH2: β: 0.01; p = 0.01; 95% CI: [0.002; 0.02]). The gene discussed is SLC6A4; the disease is major depressive disorder.