CSF2 and congenital rubella syndrome: The lack of clonal expansion and secretion of interleukin (IL)-3 and granulocyte-macrophage colony stimulating factor (GM-CSF) on NK cell activation makes cytokine release syndrome (CRS) unlikely, since the condition is mostly attributed to interferon (IFN)-γ, tumor necrosis factor (TNF)-α, and IL-6 secreted by activated T cells and IL-1 from macrophages [14].