ERBIN (Erb-B2 Receptor Tyrosine Kinase 2 Interacting Protein) is a protein that interacts with the ErbB2 receptor, which is important for cell growth and differentiation. ERBIN helps regulate signaling pathways linked to ErbB2 and other cellular processes, and it has been studied for its potential role in cancers where ErbB2 activity is involved, such as breast cancer.