The fixed-effects model showed that moderate COVID-19 patients had higher levels of pooled GFAP when compared to the healthy controls (SMD = 0.83; 95% CI: 0.63, 1.02; Z = 8.16; p ≤ 0.001; I2: 0%) (the third panel from the top, Figure 3). The gene discussed is GFAP; the disease is COVID-19.