The NPM/ALK fusion gene was confirmed by fluorescence in situ hybridization (FISH) analysis in more than 80% of interphase nuclei and metaphase spreads.     ///    The chromosomal 5q35 breakpoint (bp) and the expression of the NPM/ALK fusion gene are the most remarkable molecular cytogenetic features of these malignancies.     ///    "To identify new locations of ALCL-related oncogenes, comparative genomic hybridization (CGH) was applied to three ALCL cell lines (SU-DHL-1, Karpas 299, and DEL) exhibiting the 5q35 bp and expressing the NPM/ALK transcript. "