Cripto-1 knock-down inhibited the invasion of CNE-2 cell lines. Effects of Cripto-1 knockdown on cell invasive potency were determined by an in vitro invasion assay. (A) 48 hr after seeded, the cells on the upper chambers were removed, and the invasive cells on the lower surface of the membrane were fixed and stained with hematoxylin, and visualized at ×200 magnification. a: CNE-2, b: CNE-2/GFP+/mock, c: CNE-2/GFP+/Cripto-1-. (B) The cells on the lower surface of the membrane were counted in five randomly selected fields. Each value represents the average of triplicate determinations expressed as the mean ± SD. (* p < 0.01).