Kallistatin inhibits the migration and invasion of prostate cancer cells. Kallistatin (1 μM) prevented tissue kallikrein (TK, 0.1 μM)-induced (A) migration and (B) invasion of DU-145 prostate cancer cells. Wild-type kallistatin (KS, 1 μM), but not heparin-binding site mutant kallistatin (HMKS, 1 μM), antagonized epidermal growth factor (EGF, 1 ng/ml)-induced (C) migration and (D) invasion of DU-145 prostate cancer cells, indicating that kallistatin’s effects are mediated via its heparin-binding domain. n=3, *P<0.05 vs. other groups.