This is of particular interest as commensal enterococci specifically stimulate TLR2 on immune cells via lipoteichoic acid (226); therefore, and based on preliminary data evaluating the impact of the microbiome on toxicity and efficacy of CARTs (181) we hypothesize that an intestinal expansion of enterococci and the co-occurrence of severe CRS in CART treated patients may be due to a direct effect of Enterococcus spp. on CARTs via TLR2. The gene discussed is TLR2; the disease is congenital rubella syndrome.