Flament et al. reported that in severe COVID-19, the MAIT cell phenotype undergoes a progressive shift from a type I IFN immune profile to an IL-18 immune environment, mediated by a transcriptional switch in monocytes and macrophages, which suggests that IL-18 can drive both protective and pathogenic MAIT cell responses, depending on the disease context [105]. Here, IL18 is linked to COVID-19.