BMX (bone marrow X kinase) is a cytoplasmic tyrosine kinase identified by reverse transcription of mRNA isolated from human bone marrow and mapped to the chromosomal band Xp22.2. The full length protein is 675 amino acids with a tyrosine kinase domain, an amino terminal pleckstrin domain, as well as an SH3 and SH2 domain. Direct comparison of BMX's primary sequence with other kinases showed that this is highly related to the family of BTK/ITK/TEC. BMX kinase is expressed in fetal and adult tissues, with the highest expression in heart, testis, small intestine and colon. It is undetectable in spleen, brain, kidney, and pancreas. Further analysis of mRNA expression showed that BMX is expressed in hematopoietic tissues and neutrophilic granulocytes, and in patients with acute and myeloid leukemia. The levels of BMX mRNA were substantially lower in patients with acute and chronic lymphoid leukemias, thus suggesting that BMX may be important during myelopoiesis.CST:It is expressed in a variety of hematopoietic, epithelial and endothelial cells.