CCL25 also known as C-C motif chemokine 25 isoform 1. CCL25 is potentially involved in T-cell development. Recombinant protein shows chemotactic activity on thymocytes, macrophages, THP-1 cells, and dendritics cells but is inactive on peripheral blood lymphocytes and neutrophils. It binds to CCR9. Isoform 2 is an antagonist of isoform1 and binds to atypical chemokine receptor ACKR4 and mediates the recruitment of beta-arrestin (ARRB1/2) to ACKR4. Recombinant human CCL25-iso1, fused to His-tag at N-terminus, was expressed in E.coli .