Research into the structure and function of oncogenes has been a major endeavor for many years. The first chromosome rearrangement (Ph') involving a proto-oncogene to be directly associated with cancer induction was identified in 1960. Since then, over 50 proto-oncogenes have been mapped in the human genome, and many cancer-related mutations have been detected. nce the role of oncogenes and proto-oncogenes in cancer was understood, the task of elucidating the exact mutations, specific breakpoints for translocations, and how protein products are altered in the disease process was undertaken.

Karyotype analysis has been used for many years to identify chromosome abnormalities that are specifically associated with particular types of leukemia and lymphoma aiding in diagnosis and the understanding of prognosis. ow that many of the genes involved in the chromosome rearrangements have been cloned, newer, more effective detection techniques, have been discovered. ISH, fluorescence in situ hybridization, uses molecular...