CD40LG and COVID-19: Patients with COVID‐19 show significantly higher protein levels of APRIL (COVID‐19: 77.4 ng/mL vs. HD: 40.7 ng/mL, p < 0.0001); LIGHT (COVID‐19: 0.60 pg/mL vs. HD: 0.43 ng/mL, p < 0.05); CD30L (COVID‐19: 4.5 ng/mL vs. HD: 2.5 ng/mL, p < 0.0001); and CD40L (COVID‐19: 29.3 ng/mL vs. HD: 19.6 ng/mL, p < 0.01) (Figure 3A–D, respectively).