CD33 and acute myeloid leukemia: After confirming that there were no residual B-cells or plasma cells in the samples by flow cytometry analysis, we detected the IGKV/IGKJ transcripts in CD33+ myeloblasts from all 6 AML cell lines and 17/18 AML patients, but not or only rarely in neutrophils (0/8) and monocytes (1/8) from healthy individuals.