Chromosome 2:3 translocation in cancer. Fluores- cence in situ hybridization (FISH) micrograph of chromosomes from a cancer patient, showing 2:3 translocation. Chromosomes are elongated, coming from the nucleus (round, lower left). Chromosomes 2 and 3 fluoresce pink and light blue; segments of these chromosomes have translocated so that part of chromosome 2 is attached to 3, and 3 to 2. The sharing of genetic segments is a subject of cancer research. In some cancers, like leukaemia, trans- location occurs and may be a cause of cancer. The FISH technique enables chromosomes to be tagged with fluorescent dyes to highlight genetic traits. Photographed at Cytocell Ltd., England.