In these models, CARs with a 4-1BBζ endodomain caused severe GVHD, allogeneic T-cells transduced with a first-generation CAR (CD3ζ endodomain only) had a minor decrease in GVHD severity, and in contrast, the CD28ζ CAR was associated with a significantly lower rate of GVHD when compared to the 4-1BBζ CAR and control vector [12]. Here, CD247 is linked to graft versus host disease.