IL6 and congenital rubella syndrome: Moreover, cytokine-release syndrome (CRS) and neurotoxicity are less likely to occur in CAR-NK immunotherapy partly due to a different spectrum of the secreted cytokines: activated NK cells usually produce IFN-γ and GM-CSF, whereas CAR-T cells predominantly induce cytokines, such as IL-1a, IL-2, IL-6, and tumor necrosis factor alpha that are positively associated with CRS and severe neurotoxicity.87,88