Definitive evidence of this was provided analyzing a cohort of 213 patients with hormone receptor-negative, node-positive, early breast cancer, of any HER2 status, and with a long-term follow-up (median, 11.3 years), who were randomized in an adjuvant phase III trial (IBCSG 22-00)35 to low-dose metronomic MTX-based maintenance chemotherapy (cyclophosphamide + MTX, CM) for 1-year or no maintenance chemotherapy at the end of standard adjuvant treatments. Here, ERBB2 is linked to breast cancer.