Many chemokines enhance SLC- and ELC-induced migration in CCR7-transfected cells. CCR7-transfected cell migration induced by 10 nM SLC (A) or ELC (B) in the presence of 1 μM of different chemokines applied to the lower wells as indicated. Percentage values of the chemotactic increases were calculated as follows: the number of migrated cells at the suboptimal chemotactic concentration (10 nM SLC or ELC) was subtracted from the number of migrated cells at the optimal chemotactic concentration (100 nM SLC or ELC), with the difference representing 100% of the chemotactic increase (C). Synergistic effects are given as the percentage of the chemotactic increase. DC-CK1, dendritic cell-specific CC-chemokine; GCP, granulocyte chemotactic protein; GRO, growth-regulated oncogene; IP, interferon-inducible protein; NAP, neutrophil-activating peptide; RANTES, regulated on activation normal T cell expressed and secreted; SDF, stromal cell-derived factor; and TARC, thymus activated-regulated chemokine.