IL6 and congenital rubella syndrome: Risk factors for CRS vary between studies and include high tumor burden (or elevated lactate dehydrogenase [LDH] as a surrogate marker thereof) [23], conditioning regiment, dose and type of CAR-T cell product infused, as well as elevated biomarkers of inflammation (C-reactive protein [CRP], IL6 levels, Ferritin) and endothelial activation prior to and in response to therapy [40,41].