RUNX1 and neoplasm: For example, RUNX1 is a frequent target of chromosomal translocations in hematopoietic malignancies,20 and the loss or reduction of RUNX3 expression can be detected in over 80% of gastric cancers.21,22 These observations strongly suggest that RUNX1, as well as RUNX3, acts as a putative tumor suppressor.