Walter et al. (2020) presented a retrospective analysis of 4695 patients with hormone receptor-positive and HER2-negative early breast cancer (T1-3: tumour size ≤ 5m; N0-1: node-negative/micrometastasis/one to three nodes positive; M0: no distant metastasis), who had been tested for ODX-RS in Germany in the period between November 2015 and July 2018. Here, ERBB2 is linked to breast carcinoma.