ERBB2 and metastatic neoplasm: Our results and these published data on the stability of HER2 status between primary and metastatic tumours are in contrast with the recently published studies by Schmidt-Kittler et al (2003) and by Klein et al (Mercapide et al 2002) showing that micrometastatic cells demonstrated fewer chromosomal alterations, such as losses and gains detected by single-cell CHG analysis, than primary tumour cells (Mercapide et al 2002; Schmidt-Kittler et al, 2003).