Human CD44 Antigen (CD44) Protein

Background

CD44 is a type I transmembrane glycoprotein and an important cell surface receptor involved in various physiological and pathological processes. It is expressed on a wide range of cells, including hematopoietic cells, epithelial cells, fibroblasts, endothelial cells, and neurons. CD44 plays a crucial role in cell-cell and cell-matrix interactions, facilitating processes such as cell adhesion, migration, proliferation, and differentiation. The most well-studied ligand of CD44 is hyaluronic acid (HA), a major component of the extracellular matrix (ECM), which mediates a variety of cellular responses. CD44 is implicated in numerous biological processes, including immune response modulation, tissue repair, inflammation, and cancer metastasis. The molecule is often referred to as a "stem cell marker" due to its elevated expression in several types of cancer stem cells.