Other data from our laboratory indicated that CD45 immunoprecipitated from KG1a cells (a human CD34+ AML cell line that expresses the well-characterized glycoprotein E-selectin ligands HCELL, CD43-E, and CLA (16, 19, 20)) migrated on SDS-PAGE gel at this molecular weight. This evidence concerns the gene CD44 and acute myeloid leukemia.