However, two cases of upper gastrointestinal hemorrhage which occurred in the period of CART cell infusion and 11 days after the infusion of CART cells respectively warned us the on-target off-tumor threat of HER2-targeting CART cells because of the expression of HER2 antigen on gastrointestinal mucosa though with a lower density when compared with tumor tissues (Hynes and Lane, 2005). Here, ERBB2 is linked to neoplasm.