IL1B and susceptibility to pneumonia measurement: Around the tenth day after diagnosis, ∼20% of patients with coronavirus disease 2019 (COVID-19)−associated pneumonia evolve toward severe oxygen dependence (stage 2b) and acute respiratory distress syndrome (stage 3) associated with systemic inflammation often termed a “cytokine storm.” Because interleukin-1 (IL-1) blocks the production of IL-6 and other proinflammatory cytokines, we treated COVID-19 patients early in the disease with the IL-1 receptor antagonist, anakinra.