Schematic diagram of the wild-type proteins of AML1 and MTG16, the chimeric proteins AML1-MTG16 type 1 and type 2, and the reciprocal chimeric protein MTG16-AML1 type 1R detected in patient no. 1. Vertical arrowheads indicate breakpoints of AML1 and MTG16. Horizontal arrowheads indicate the location of primers used for RT-PCR. Regions that correspond to the structural or functional domains of the proteins are shown: runt, runt domain; PST, proline/serine/threonine-rich region; NHR1-3, Drosophila Nervy homologous region 1-3; Zn finger, zinc finger domain. Nucleotide sequences and positions near the junction of chimeric proteins are also shown and those derived from MTG16 are indicated by italic.