Induction of AS283 lymphoma cell motility by Tat-MBP. Motility response of AS283 lymphoma cells to increasing amounts of Tat-MBP (2 to 200 ng/mL). Control medium, Tat-MBP, and MBP were used as attractants in the presence of heparin (0.5 μg/mL). Data are expressed as the number of migrated cells in 20 high-power fields. Columns, mean of three replicates and representative of 1 out of 3 experiments; bars, SD. *P < .001 compared with control.