This article highlights recent advances in the molecular structure and
function of proteins that are activated or created by chromosomal abn
ormalities and discusses their possible role in tumor development. The
molecular characterization of these proteins has revealed that tumor-
specific fusion proteins are the consequence of most chromosome transl
ocations associated with leukemias and solid tumors. An emerging commo
n theme is that creation of these proteins disrupts the normal develop
ment of tumor-specific target cells by blocking apoptosis. These insig
hts identify these chromosomal translocation-associated genes as poten
tial targets for improved cancer therapies.