IL2 and COVID-19: Finally, a recent study has shown that the cocktail of the cytokines found most highly upregulated in the circulation of patients with COVID-19 and in PBMCs infected with SARS-CoV-2, i.e. IL-6, IL-18, IFN-γ, IL-15, TNF-α, IL-1α, IL-1β, and IL-2 robustly induced cell death the marrow-derived macrophages whereas none of the cytokines individually induced high levels of cell death at the concentration used.