CCL22 is a C-C motif chemokine that functions as a selective chemoattractant for immune cells, with primary roles in T cell trafficking and immune regulation. It exhibits potent chemotactic activity for chr16 activated T lymphocytes, monocytes, dendritic cells, and natural killer cells, but not for resting T cells or neutrophils, operating through its cognate receptor CCR4 1. CCL22 is a key component of the anti-inflammatory microenvironment produced during M2 macrophage polarization 2, where its expression is upregulated by CD40 stimulation on B cells 3. In cancer immunology, CCL22 produced by tumor cells and macrophages mediates trafficking of regulatory T cells (Tregs) to tumor sites, promoting immune privilege and correlating with reduced survival in ovarian carcinoma 4. The CCL22-CCR4 axis also operates in CNS autoimmunity, where it contributes to experimental autoimmune encephalomyelitis pathogenesis and multiple sclerosis progression 5. Beyond immunity, macrophage-derived CCL22 regulates adaptive thermogenesis through eosinophil CCR4 signaling, promoting adipose beiging and reducing obesity-associated metabolic dysfunction 6. In human obesity, elevated circulating and tissue CCL22 correlates with metabolic dysfunction and vascular inflammation 7. Overall, CCL22 functions as a regulatory hub controlling immune suppression, metabolic adaptation, and vascular pathology through coordinated CCR4-mediated signaling.