Genetic alterations in leukemias and lymphomas: impressive progress and continuing complexity.

Cytogenetic clues and molecular techniques have led to the identification of a very large number of genes involved in the pathogenesis of human leukemias and lymphomas, most of them previously unknown and many of them "activated" by chromosomal translocations. The oncogenic effects of most of these genes are narrowly restricted to a particular cell lineage or stage of differentiation. Research is continuing on the mechanisms by which various types of cancer genes participate in the development of hemic neoplasms, and on how this information can be effectively utilized to develop new clinical approaches to the control of these disorders.