In the study by Terriou et al. (13), half of the CEBPA methylated T-ALL cases were CALM/AF10 positive (5/10), suggesting that the search of CALM/AF10 in CEBPA methylated AML could help distinguish between the immature T-ALL and myeloperoxidase negative AML. The gene discussed is MPO; the disease is acute lymphoblastic leukemia.