CD9 antibody targets the CD9 protein, a member of the tetraspanin family characterized by four transmembrane domains. CD9 is widely expressed on the surface of various cell types, including immune cells, stem cells, epithelial cells, and cancer cells. It plays critical roles in regulating cell adhesion, migration, signaling, and membrane fusion by forming dynamic complexes (tetraspanin-enriched microdomains) with integrins, growth factor receptors, and other tetraspanins. CD9 is implicated in physiological processes like platelet aggregation, neuronal development, and fertilization, as well as pathological conditions such as cancer metastasis and viral infection.
CD9 antibodies are essential tools for studying its expression and function. They are widely used in flow cytometry, immunohistochemistry, and Western blotting to identify CD9-positive cells or assess protein levels. In cancer research, CD9 antibodies help explore its dual role as either a tumor suppressor or promoter, depending on context, due to its involvement in cell motility and signaling pathways. Additionally, CD9 antibodies have therapeutic potential; for example, they may inhibit exosome-mediated intercellular communication in tumors. However, variability in antibody performance (due to epitope specificity or glycosylation differences) requires careful validation for experimental reproducibility.