CXCL10 and COVID-19: We also observed a > 2-fold increase in IL-15 in COVID-19 patients (2.3 ± 0.1 for controls vs. 5.7 ± 0.8 pg/mL for COVID-19 patients) and a 10-fold increase in CXCL10/IP-10 over controls (401.5 ± 75.5 pg/mL controls vs. 4257.0 ± 1383.1 pg/mL COVID-19 patients, p < 0.001).