Exogenous pyrogens are released by organism which further trigger release of endogenous pyrogens called cytokinins, which are interleukin 1,2,6 (IL1, IL2, IL6), Tissue Necrotic Factor (TNF) and Interferon alpha (INF).7 This cytokinins thereby acts on hypothalamus to elevation of the hypythalamic set point by increasing prostaglandin E2 (PGE2).8 Fever in COVID-19 is also due to similar mechanism causing release of cytokines secondary to tissue damage or hypoxia. The gene discussed is IL2; the disease is COVID-19.