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-1β (p = 0.04), and suggestive but non-significant interactions between Hispanic and procalcitonin (p = 0.07) and IL-8 (p = 0.09) as compared to NH White (Supplementary Table 6). The gene discussed is CXCL8; the disease is COVID-19.