SETDB1 and cancer: Its mechanism underlying such catalytic process may be that SETDB1 binds to HP1 and its co-repressor KAP1 in heterochromatin, thus promoting the formation of H3K9me3 and mediating the heterochromatin gene silencing.14, 15 It has been proven that SETDB1 is highly expressed in a variety of malignant tumors,16, 17, 18 and it is closely related to the proliferation and invasion of tumor cells.