However, different IGKV/IGKJ usages were detected in different cell lines, with the exception that IGKV1-NL1*01/IGKJ5*01 was expressed by 3 of 5 AML cell lines, including HEL, NB4 and KG-1 (Table 1). Here, IGKJ5 is linked to acute myeloid leukemia.