IL4 and COVID-19: Thus, the research aim was to characterize the expression levels of IL-2, IL-4, IL-6, IL-10, TNF-α, and IFN-γ in peripheral blood leukocytes and to assess the relationship between expression levels and the risk of death among individuals older than 60 years old who had COVID-19 and were admitted to the unique referral hospital in Cartagena de Indias, Colombia.