IL6 and COVID-19: Profiling proinflammatorycytokines like interleukin-6 (IL-6) inbody fluids offers critical insights into immune responses relatedto conditions such as sepsis, myocardialinfarction, COVID-19, and neurodegenerative disorders. Monitoring IL-6 in the whole blood, serum, or plasma is particularlyvaluable for assessing the inflammation severity, for prognostication, and for identifying subphenotypes with the potential to guide novel therapies.