In the study conducted by Müller et al., which is part of the clinical trial “Changes in serum levels of miR-21, miR-210, and miR-373 in HER2-positive breast cancer patients undergoing neoadjuvant therapy: a translational research project within the Geparquinto trial” (ID: NCT00567554), the dysregulation of miRNAs 21, 210, and 373 was evaluated before and after HER2 + BC patients received chemotherapy based on trastuzumab and lapatinib. The gene discussed is ERBB2; the disease is breast carcinoma.