In the preclinical study, it was found that CD276-CAR-NK-92 cells showed significantly enhanced cytotoxicity to U-937 or U-937 CD19/tag AML cell lines after a gene knockout of three different inhibitory checkpoints (CBLB, NKG2A, TIGIT) in CAR-NK cells with CRISPR-Cas9 technology [56]. This evidence concerns the gene KLRC1 and acute myeloid leukemia.