KLRB1 and testicular germ cell tumor: In this study, KLRB1 and CCR7 were found to be barely expressed in normal human bone marrow, but highly expressed in AML bone marrow, and besides AML, they were also over-expressed in a few types of cancers, such as testicular germ cell tumors (TGCT), kidney renal clear cell carcinoma (KIRC), pancreatic cancer (PAAD), etc., and the tissues of the three cancers studied were not closely related to the bone marrow, so KLRB1 and CCR7 will be bone marrow biomarkers helpful for the diagnosis of AML.