Vol. 6, Issue 2, Part A (2024)

Cytokeratin 5 (CK5) is a type II intermediate filament protein predominantly expressed in the basal epithelial cells of various tissues, including the breast. In breast tissue, CK5 plays a crucial role in maintaining the structural integrity and function of myoepithelial cells, which are essential for proper breast development and homeostasis. This review aims to provide a comprehensive analysis of CK5's role in breast lobular myoepithelial cells, focusing on its expression patterns, regulatory mechanisms, and potential implications in breast cancer pathogenesis. By exploring the current literature, this review will highlight the importance of CK5 as both a marker for myoepithelial cells and a potential diagnostic and prognostic tool in breast cancer, particularly in lobular carcinoma. Additionally, the review will discuss the potential of CK5 as a therapeutic target, considering its involvement in epithelial-mesenchymal transition (EMT) and tumor invasion.