We have characterized the composition of the Fabrack-CAR (eg, linker and transactivation sequences), used multiple meditope-enabled Fabs, characterized the activation (eg, CD107a and IFNγ expression) as a function of antigen density, demonstrated that combinations of memAbs with different antigen specificities target antigen presenting cells, and demonstrated in vivo that the Fabrack-CAR T cell eliminated tumor xenografts individually or as a combination. Here, IFNG is linked to neoplasm.