For this reason, and particularly in Europe, a confirmation of HER2 gene amplification by FISH became mandatory for a patient's inclusion in a clinical trial using Herceptin®, when the corresponding tumour is scored 2+ by IHC (Hoang et al, 2000; Ridolfi et al, 2000; Diaz, 2001; Tubbs et al, 2001; Vogel et al, 2002). This evidence concerns the gene ERBB2 and neoplasm.