Study of cell motility by wound healing assay. A wound healing assay was used to evaluate the migration of SK-BR-3 cells after silencing IKKε. Fifty-six hours after the transfection of siRNA, cells were wounded and monitored with a microscope every 12 hours. The migration was determined by the rate of cells filling the scratched area. The normalized wound area was calculated by the software TScratch . Similar results were obtained in three independent experiments. NC, negative control siRNA.