Itacitinib successfully reduced cytokine levels associated with CRS in a murine model of hyperinflammation, reduced IL-6 production by macrophages in vitro and in vivo, reduced cytokines production by CART cells, and had no impact on CD8+ T cell or CART cell expansion or target lysis at lower doses that are pharmacologically relevant. This evidence concerns the gene CD8A and congenital rubella syndrome.