TNFSF13B and COVID-19: A similar profile is observed for systemic BAFF levels; COVID‐19 patients have higher BAFF levels compared to HD (2.7 ng/mL vs. 1.3 ng/mL, p < 0.05) (Figure 2D), and also, severe cases display higher levels (severe 3.7 ng/mL) than mild or moderate cases (1.1 ng/mL, p < 0.001; 1.9 ng/mL, p < 0.05) (Figure 2E), and moderate cases have higher levels than mild cases (p < 0.01).