Runt-related transcription factor 1 (RUNX1; also known as AML1) is a gene that codes for the alpha subunit of the core binding factor protein. This protein is thought to take part in regulating expression of multiple genes involved in normal hematopoiesis (Gene 2013; Kurokawa and Hirai 2003). RUNX1 is involved in translocations observed in hematologic malignancies, including AML, ALL, and myelodysplastic syndromes. Its role in cancer is also being investigated in promyelocytic leukemia, as well as in solid tumors such as endometrial, ovarian, and breast cancer. In addition, germline RUNX1 mutations, deletions, and translocations have been associated with conditions that predispose individuals to myeloid malignancies (Cazzola, Della Porta, and Malcovati 2013; Michaud et al. 2002; NCCN 2014; Song et al. 1999).