A German expert opinion on Her2/neu testing states more precisely that "...for reliable diagnosis of Her2/neu status the specific number of particles is less relevant than the quality of biopsies and the number of actual tumour-containing particles obtained" and calls for five tumour-containing particles from different tumour areas to avoid false-negative results due to the high intra-tumoral heterogeneity of Her2/neu11. This evidence concerns the gene ERBB2 and neoplasm.