Twenty-fi ve years ago the amplifi cation of the HER2 gene and its protein overexpression was fi rst described in gastric cancer [1]. Twenty years later a group of Spanish investigators fi rst experienced the activity of trastuzumab in patients with HER2 overexpressing gastric cancer [2]. Meanwhile, a randomised multi-national trial (ToGA) made things even clearer and brought trastuzumab to regulatory approval and marketing authorisation in Europe and other parts of the world. ToGA could show that the addition of trastuzumab to standard chemotherapy can prolong the survival of patients with incurable HER2 overexpressing gastric cancer [3]. The benefi t is somewhere between 2.7 months (primary endpoint: all included patients) and 5.6 months (subgroup of patients with HER2 gene amplifi cation and score 3+ protein expression). Things look simple at figlance: Trastuzumab, a monoclonal antibody directed against the HER2 receptor protein, is effective in HER2-positive advanced gastric cancer and should be used in this disease in combination with standard platinum-5FU chemotherapy. But oncology would not be oncology if things remained so simple at a more in-depth analysis. Our current challenge with HER2-positive gastric cancer is to make the true nature of every individual disease visible and to translate our fi ndings to the best available treatment recommendation. Our translator in this critical venture is our highly respected partner, the molecular pathologist, who‐ more than ever‐is an integral part of the multidisciplinary treatment team. Pathologists and clinicians know that‐for the best of