IGF1R and Ewing sarcoma: Natural killer (NK) cells and chimeric antigen receptor (CAR)-based immunotherapy for adoptive cellular immunotherapy have been applied for the effective treatment of ES, inducing the activation and expansion of NK cells by inhibiting IGF-1R expression, without affecting the immunophenotypes of NK cells and their degranulation response to ES cells, and subsequently maintaining potent antitumor effects against ES cells (Jamitzky et al., 2015).