The circulating microRNA(s) identified in this dataset will be confirmed on independent case series collected in the prospective phase II NeoGENE trial (as the testing dataset), a multicenter, academic Italian study aimed at profiling HER2-positive tumor tissues before and after conventional trastuzumab-based therapy with the aim of studying tumor tissue and the plasma biomarkers of the response to treatment. This evidence concerns the gene ERBB2 and neoplasm.