Tiam1 supports breast cancer cell motility in wound-healing assays. Plates of confluent MDA-MB-231 and MDA-MB-453 cells were transfected overnight with 200 nM control (si Ctrl) or Tiam1 (si Tiam1) siRNA. Cells were then examined in a wound-healing assay, as described in Materials and Methods. Wound closure was measured at 12 hours (MDA-MB-231) or 24 hours (MDA-MB 453). Orange lines indicate the original wound edges. Images are representative of at least 10 independent locations that were monitored over the length of each wound. Orange lines indicate original wound edge.