In 1997, a mouse model of promyelocytic leukemia was developed by Washington University – St. Louis researcher Timothy J. Ley, MD and associates. Approximately 30% of transgene- expressing mice eventually developed acute myeloid leukemia after a long latent period. 

Acute promyelocytic leukemia (APML) is characterized by abnormal myeloid development, resulting an accumulation of leukemic promyelocytes that are often highly sensitive to retinoic acid.