Patients with PPMS exhibited a strong correlation between CD14+ monocyte frequency and GFAP levels [rSP = 0.926, (95% CI: 0.571–0.989), P = 0.024] (Fig. 4F), along with multiple significant associations between T cell subsets and GFAP levels (Supplementary Table 2). The gene discussed is GFAP; the disease is primary progressive multiple sclerosis.