Fixed-effects meta-analysis of the overall pooled GFAP revealed a significant difference between patients with severe COVID-19 and healthy controls (SMD = 1.00; 95% CI: 0.81, 1.18; Z = 10.57; p ≤ 0.001; I2: 0.0%) (bottom panel, Figure 3). This evidence concerns the gene GFAP and COVID-19.