The canine ERBB2 gene maps to a chromosome region frequently affected by aberrations in tumors of the dog (Canis familiaris). 
The dog offers an increasingly important model for several human diseases, including cancer.  Accordingly, the results of canine gene mapping studies will be of considerable significance.  Herein, we have addressed the mapping of the canine gene ERBB2 (alias HER2, NEU).  ERBB2 is a protooncogene encoding a tyrosine kinase receptor protein, the overexpression of which correlates with a more rapid progression and a worse prognosis in breast cancer.  In addition, it apparently plays a role in the development of other tumors as well.  By fluorescence in situ hybridization (FISH), we have mapped the canine ERBB2 to 1q13.1.  Cytogenetic studies of canine tumors revealed that this region is very often affected by clonal chromosome aberrations in tumors of the dog.