CCL21 and neoplasm: The resultant protein includes a long C-terminal domain that can combine with glycosaminoglycans (GAGs) to affix to the cell surface or ECM,350 providing a signal that can be leveraged by lymphocytes for homing to secondary lymphoid organs and the subsequent regulation of metastatic tumor development.351 The G protein-coupled receptor CCR7 is the only receptor for CCL21, and it is expressed on the surface of immune cells, including B cells, T cells, and DCs.