The MLL-LCX fusion protein lacked a CXXC domain of LCX, but retained an alpha-helical coiled-coil region at the COOH terminus, similar to MLL-SEPTING, MLL-CDCREL1, MLL-AF1p/Eps15, and MLL-AF6, which suggests that these fusion proteins are involved in the pathogenesis of 11q23-associated leukemia through similar mechanisms.