In case p-18, a p-AML with a t(8;21), a 1Mb loss on 8q21.3 amputated the first 5′ exons of RUNX1T1, probably inactivating the ETO-AML1 chimeric gene on the der(21) and left the 3′ RUNX1T1 coding sequence intact in the AML1-ETO transcript on the der(8) [22]. This evidence concerns the gene RUNX1 and acute myeloid leukemia.