To this end, and given that most patients with HER2-positive early-stage breast cancer, in the face of different strategies to increase or decrease systemic therapy, continue to receive only chemotherapy and trastuzumab, we decided to analyze the association between pre-operative circulating miRNAs and event-free survival (EFS) of patients treated in the NeoALTTO trial (16) with trastuzumab-based therapy. The gene discussed is ERBB2; the disease is breast carcinoma.