HT1080 cell motility using modified Boyden chambers does not require MMPs. HT1080 cells were seeded onto porous (8 μm) polycarbonate membranes coated with type I collagen (1 mg/ml) and allowed to migrate for four hours in the presence of 1 μM LPA or S1P in the presence or absence of synthetic MMP inhibitors (5 μM GM6001, 5 μM TAPI-0, or 5 μM TAPI-1). Membranes were removed, stained, and migrating cells were quantitated using Scion® software and Microsoft Excel®. Data are expressed as mean number of migrating cells × 103 (± S.D.) and represent the results of quadruplicate experiments.