Myelomonoblastic leukaemia cells carrying the PEBP2beta/MYH11 fusion gene are CD34, c-KIT+ immature cells

To clarify the aspects affected by the PEBP2beta/MYH11 fusion gene involved in the inv(16), we analysed immunophenotypes in myelomonoblastic leukaemias. We found high expressions of CD34 and c-KIT antigens in myelomonoblastic cells from all patients carrying this fusion gene, including two with M4 and one CML blastic phase, in contrast to those with M4 without the fusion gene. These findings indicate that immunophenotyping is useful for detecting a leukaemia with the fusion gene in myelomonoblastic leukaemias and that the PEBP2beta/MYH11 gene is involved in immature cells expressing CD34 and c-KIT antigens.