Anti-inflammatory therapies that target particular pro-inflammatory cytokines, such as TNF-α and IL-6, have been shown to be effective treatment for mycobacterial IRIS in studies of small numbers of patients (78) but observational studies and randomized controlled trials have not provided clear evidence of a benefit of IL-6 inhibitors, such as the IL-6R blocker tocilizumab, in the treatment of severe COVID-19 (79–81). This evidence concerns the gene IL6 and COVID-19.