The lack of toxicity in NSG-MHC-KO strain in our study further supported our previous observation that affinity-tuned CAR T cells against ICAM1 neither reacted with ICAM1 expressed in mouse tissues despite its cross-reaction between human and murine ICAM141,53 nor elicited cytokine release syndrome (CRS). Here, ICAM1 is linked to congenital rubella syndrome.