In a recent immunometabolic study, strong association was seen between proinflammatory cytokines and chemokines, such as IL-6, M-CSF, IL-1α, and IL-1β with metabolites involved in amino acid metabolism, NAD+ metabolism, purine and pyrimidine metabolism, TCA cycle, and primary bile acid metabolism in severe COVID-19 patients (Xiao et al., 2021). Here, IL6 is linked to COVID-19.