(A, B) Overexpression of RANK in HEC-1A and Ishikawa cells revealed by qRT-PCR and western blotting, and the latter was further quantified by densitometry of three times. GAPDH was included as an internal control. **P < 0.01, ***P < 0.001, n = 3. (C, D) Wound-healing migration assays for HEC-1A and Ishikawa cells. The healing of wounds was imaged at 0 h and 48 h, showing that overexpression of RANK enhanced migration. The images were obtained at 100× magnification. Bar = 200 μm. (E, G) Transwell invasion assays. EC cells were grown in upper chamber for 48 h. Invaded cells were fixed, stained and imaged using an inverted microscope at 100 × magnification. Bar = 200 μm. (F, H) Graphs indicated the number of invasive cells for each group. **P < 0.01, n = 3.