CD8α is a crucial immune glycoprotein that plays a vital role in the immune response by serving as a co-receptor for the T-cell receptor （TCR） on cytotoxic T cells. It forms either a homodimer （α/α） or a heterodimer with CD8β （α/β） to interact with MHC class I molecules on antigen-presenting cells （APCs）, facilitating the recognition of intracellular pathogens such as viruses. CD8α also recruits the LCK kinase, which initiates downstream signaling pathways essential for T-cell activation and proliferation. This molecule is critical for the function of cytotoxic T lymphocytes （CTLs） and is involved in various immune-related diseases, including immunodeficiencies and autoimmune conditions.