Cytokine release syndrome (CRS), the most common toxicity observed for CAR T cell therapy, is a cascade of immunological events initiated by the synchronous release of cytokines from overactivated T cells, such as IFN-γ and IL-2, which in turn activate neighboring myeloid cells and macrophages to release additional inflammatory cytokines, for instance, IL-68,9. Here, IL2 is linked to congenital rubella syndrome.