CXCL8 and COVID-19: To validate the population-specificity of these COVID-19 mortality-associated immune markers, we further utilized a multivariate model including interaction terms, finding a significant interaction between NH Black and IL-1B (p=0.04) and a suggestive but non-significant interactions between Hispanic and procalcitonin (p=0.07) and IL-8 (p=0.09) compared to NH White (Supplemental Table 6).