CCL27, also known as CTACK (C-C Motif Chemokine Ligand 27), is a chemokine primarily involved in the recruitment of T cells, particularly skin-homing memory T cells, to sites of inflammation. It is mainly produced by keratinocytes in the skin, as well as by other epithelial cells. CCL27 plays a key role in immune responses in the skin, contributing to the development of conditions like psoriasis, eczema, and other inflammatory skin diseases. By attracting T cells to the skin, CCL27 helps regulate immune responses and inflammation, making it an important factor in both normal skin immunity and dermatological disorders.