CSF2 and congenital rubella syndrome: The most significant and common toxicity of CAR T-cell therapy is CRS, an inflammatory syndrome caused by multiple cytokines, including interferon γ, interleukin (IL)-1, IL-2, IL-4, IL-6, IL-8, IL-10, TNF-α and granulocyte/macrophage colony-stimulating factor (GM-CSF), produced by the CAR T cells themselves and by other cells [62].