Rearrangement and coamplification of the 8p12 and 11q13 chromosomal regions occurs in a significant proportion of breast cancers. It usually involves a complex hybrid structure in which the FGFR1 and CCND1 genes are amplified. We report here a different type of 8p12-11q13 rearrangement in the MDA-MB-175 mammary carcinoma cell line. This amplification contains the NRG1/HGL (from 8p12-21) and DOC4 (from 11q13) genes, encoding respectively a ligand for ERBB receptors and a stress-induced protein which is a mammalian ortholog of Drosophila Tenm/Odz. It has been shown previously (Wang et al, Oncogene 18: 5718-5721, 1999) that these two genes are rearranged and fused by a translocation event. This type of event was not found in 30 tumors tested that showed coamplification of the 8p12 and 11q13 regions.