More importantly, the CART-aIL6/IL1RA with GM-CSF/TCR KO targeting CD19 displayed comparable cytotoxicity against CD19+ Nalm6 leukemia cells stably expressing GFP as the GM-CSF wild-type counterpart (Fig. 2h), proving that gene editing of GM-CSF did not affect the killing capacity of CART in vitro. Here, CD19 is linked to leukemia.