CD44 and COVID-19–associated multisystem inflammatory syndrome in children: Analysis of CD4+ T cells of Foxp3EGFPCreR26N1c/+ mice revealed that their activation phenotype recapitulated that of CD4+ T cells of patients with MIS-C, including increased memory markers (CD44+CD62L–) and heightened IFN-γ production by both Tregs and Tconv cells (Figure 5, E–G).