IL6 and neoplasm: The tumor cell eradicated by activated CAR-T cells lead to the first wave of proinflammatory cytokine production including GM-CSF, IL-1β, IFN-γ, and TNF-α.[7] The elevated cytokines production in turn triggers another wave of cytokines including IL-6, IL-8, and IL-10, which originate from bystander myeloid cells such as macrophages and nonimmune cells like vascular endothelial cells.