Chemokines are a family of small molecule peptides that can induce the cells of migration.According to the relative position of the N-terminal cysteine in its molecular structure, it is mainly divided into four types.Chemoattractant cytokine ligand(CCL) 17 is a type of CC-type chemokine, also known as thymus and activation regulated chemokine (TARC). Chemokines exert biological functions through chemokine receptors(CCR) on the cell surface.The membrane receptor corresponding to CCL17 molecule is CCR4, which is mainly expressed on the cell membrane surface of various T lymphocyte subsets.The study found that CCL17 has diverse biological functions, which can chemotaxis of CCR4-positive cells.CCL17 is involved in various pathological and physiological processes such as inflammation, hypersensitivity and autoimmune diseases in the body.In recent years, it has been reported that CCL17 participates in tumor microenvironment and affects tumor immune function.Studies have found that CCL17 may play a role in promoting tumor growth and metastasis through regulatory T cells, but there are also reports that CCL17 also has anti-tumor immunity under specific conditions.

Chemoattractant cytokine ligand; chemokine receptors; Treg; Tumor microenvironment; Immune response