CCL22 also known as MDC is one of several Cys-Cys (CC) cytokine genes clustered on the q arm of chromosome 16. plays a crucial role in immune response, particularly in chronic inflammation and recruitment of immune cells to sites of tissue damage or infection. CCL22 protein is primarily expressed in thymus and spleen, where CCL22 protein facilitates homing of dendritic cells and lymphocytes, thereby influencing adaptive immune response. CCL22 protein interaction with high-affinity receptor, CCR4, predominantly found on T helper type 2 polarized cells, underscores importance in directing lymphocyte trafficking and modulating immune responses. This chemokine is particularly significant in systemic immunity, as CCL22 protein helps guide T cells to areas where needed most, such as inflamed tissues.