May play a role not only in inflammatory and immunological responses but also in normal lymphocyte recirculation and homing. May play an important role in trafficking of T-cells in thymus, and T-cell and B-cell migration to secondary lymphoid organs. Binds to chemokine receptor CCR7. Recombinant CCL19 shows potent chemotactic activity for T-cells and B-cells but not for granulocytes and monocytes. Binds to atypical chemokine receptor ACKR4 and mediates the recruitment of beta-arrestin (ARRB1/2) to ACKR4. Interacts with TNFAIP6 (via Link domain). Expressed at high levels in the lymph nodes, thymus and appendix. Intermediate levels seen in colon and trachea, while low levels found in spleen, small intestine, lung, kidney and stomach. Belongs to the intercrine beta (chemokine CC) family. CCL19 entry