KLRK1 and acute lymphoblastic leukemia: NKG2D ligands are present in tumor cells of various origins, including colorectal cancer, ovarian carcinoma, pancreatic cancer, prostate cancer, acute lymphoblastic leukemia, lymphomas and in a number of cancer cell lines, indicating the applicability of NKG2D CAR-T cells for the therapy of hematological and solid tumors [77].