CD7 and neoplasm: Although K12 CAR-T cells had similar cytotoxicity toward CD7-positive tumor cell lines as scFvCD7 CAR-T cells in short-term cytotoxicity assays, K12 CAR-T cells were more prominently activated and secreted more IFN-γ and had a prolonged persistence in vitro compared to scFvCD7 CAR-T cells.