Our preclinical in vitro data show enormous potential to improve immunotherapy of ERBB2-positive high-risk rhabdomyosarcoma a still incurable, rapidly lethal disease, assigning to NK-92/5.28.z cells rather than to unmodified parental NK-92 cells a multifarious role as ERBB2-specific CAR-targeted killers and modulators of endogenous adaptive immunity of the host, justifying the further evaluation of this approach in in vivo mouse xenograft models as a prerequisite for a possible future phase I/II clinical trial in defined subsets of high-risk rhabdomyosarcoma patients. The gene discussed is ERBB2; the disease is rhabdomyosarcoma.