<qa>  What is the most frequent target for chromosomal translocation in leukemia?The RUNX1 gene, located at chromosomal band 21q22, is a transcription factor, crucial for hematopoiesis and the generation of hematopoietic stem cells in the embryo. RUNX1 is the most frequent target for chromosomal translocation in leukemia. In addition, point mutations in the RUNX1 gene have been found to constitute an important mode of genetic alteration in development of leukemia. Recent publications stressing the clinical need for implementing RUNX1 point mutations as both a diagnostic and unfavorable prognostic marker of AML, have aroused particular interest in the functional role of RUNX1 in this disease. 