INTRODUCTION: CAR-T cell therapy, though successful in hematologic malignancies, faces challenges in solid tumors due to limitations of autologous T cells. Cytokine-induced killer (CIK) cells can be given safely across allogeneic barriers and constitute alternative effector cells generated from healthy donors. CIK cells are a heterogenous population of predominantly T cells with a mixed natural killer (NK) phenotype and combine non-MHC-restricted cytotoxicity with potent anti-tumor capacity of the adaptive immune system. Here, we characterize and compare efficacy, phenotypic subpopulations and modes of action of CAR-CIK cells and conventional CAR-T cells from same-donor samples in ErbB2+ rhabdomyosarcoma (RMS). METHODS: To benchmark CAR-CIK against conventional CAR-T cells, effector cells were generated from same-donor samples and lentivirally transduced with a second generation CD28-CD3ζ CAR. Effector subpopulations and their dynamics upon target cell exposure were phenotypically characterized by flow cytometry. Efficacy was assessed in human ErbB2+ RMS cancer cell lines and primary patient samples CONCLUSION: Our results demonstrate that CAR-CIK cells are at least equipotent to CAR-T cells. Combined with their favorable safety profile and allogeneic applicability, these findings position CAR-CIK cells as promising immune effectors for solid tumors.