IL6 and neoplasm: As is known that CRS is triggered by the activation of T cells on engagement of CARs with cognate antigens expressed by tumor cells, the activated T cells release cytokines and chemokines (including IL-2, soluble IL-2Rα, IFNγ, IL-6, soluble IL-6R, and GM-CSF), as bystander immune cells, the kinetics and exact timing of CRS induction is variable.