In contrast to the tumor-suppressive activity of p42 EBP1, reflecting the anti-apoptotic and growth-promoting activities of p482,38, p48 EBP1 is expressed at high levels in cancer cells25, including GBM6, anaplastic large cell lymphoma39, colorectal cancer40 and acute myeloid leukemia (AML)41. Here, CRLF3 is linked to acute myeloid leukemia.