Although mouse and human PTK7 protein has 90.93% homology in total sequence with 92.98% homology in the extracellular domain, which means that tumor-bearing mouse model should be suitable for the evaluation of on-target toxicity, however, we cannot evaluate the potential toxicity profiles of PTK-CAR T cells in current murine tumor models due to lack of cross-reactivity with murine counterpart of humanized antihuman PTK7 antibodies used to construct scFv part of our PTK-CARs. This evidence concerns the gene CARS1 and neoplasm.