In MIS-C patients, activation of CX3CR1+ CD8+ T cells (but not CX3CR1+ CD4+ T cells; Supplementary Fig. 4c) and IFNγ inversely correlated (Fig. 6i; N = 7, Pearson R = −0.83, p = 0.02). The gene discussed is IFNG; the disease is COVID-19–associated multisystem inflammatory syndrome in children.