Activated CX3CR1+ CD8+ T cells and activated HLA-DR+ CD38+ or Ki67+ CD8+ and CD4+ T cells are found to be more abundant in MIS-C than in patients with severe pediatric COVID-19, but HLA-DR+CD38+ CD8+ T cells frequencies decreased in the first two weeks of admission in MIS-C [45]. This evidence concerns the gene CX3CR1 and COVID-19.