ERBB2 and neoplasm: Other cell surface antigens have been investigated as CAR T cell targets in RMS: PDGFRα-CAR T cells showed good activity in vitro and tumor control in a subcutaneous RMS xenograft mouse model [26], as PDGFRα is aberrantly expressed in RMS [27]; HER2/ErbB2-CAR-engineered cytokine-induced killer cells showed potent activity on RMS spheroids [28], based on expression of the receptor tyrosine kinase HER2/ErbB2 in 10–33% of RMS at the protein level [29, 30].