[Cytogenetics, cytogenomics and cancer: 2004 update].

Cytogenetics has clearly established the key role chromosomal rearrangements play in neoplastic initiation and progression. Investigation methods have evolved considerably from banding analysis of chromosome morphology to fluorescence in situ hybridization (FISH) and now to comparative genomic hybridization (CGH) on chromosomes or micro-array analysis of DNA. In addition to its contributions to the description, prognosis and understanding of oncogenesis and tumor progression, cytogenomics provides the information required for the rational use of new targeted therapies among which Imatimib is the most achieved example.