IL6 and COVID-19: Future research should prioritize 1) mechanistic studies clarifying IL-6/hyperglycemia-induced NK cell dysfunction through combined in vivo (e.g., IL-6 transgenic models) and in vitro approaches; 2) systematic characterization of NK cell immunometabolic crosstalk with T cells/monocytes in patient samples and tissue-specific dynamics in viral target organs via spatial multi-omics; 3) multicenter prospective cohorts with sufficient sample size and longitudinal designs to establish temporal relationships between NK cell activity and COVID-19/T2D progression.