ERBB2 and breast cancer: In Human epidermal growth factor receptor 2 (HER2)-positive BC cells, upregulation of circEPSTI1 was found to promote cell proliferation, migration and invasion mediated by miR-145 sponging, leading to increased expression of Erb-B2 Receptor Tyrosine Kinase 3 (ERBB3), a tyrosine kinase receptor involved in the growth and survival of breast epithelial cells (Hamburger 2008; Zhang et al. 2022).