IL1R2 and COVID-19: IL1R2 gene, a decoy receptor [34, 35] and an endogenous inhibitor of proinflammatory cytokine interleukin-1 (IL-1), expression in monocytes was significantly (q < 0.0001) up-regulated in users of ACEi compared to nonRAAS (4.2 fold change) and COVID19-only (fold change 3.96) (Fig. 6B).