A: Caco-2 cells were treated with increasing concentrations of IAP for 48 h (0, 4, 16 mIU). Whole-cell protein were extracted and subjected to Western blotting. Primary antibodies of ERK, p-ERK, SP-1, VEGF, Cdx-2 or Claudin-2 were used for the blotting assays. β-Actin immunoblotting was performed as an internal loading control. B: Caco-2 cells were treated with 16 mIU IAP for varying lengths of time (0, 0.5, 2 or 4 h). Upper figure, levels of phosphorylated ERK detected by Western blotting. C: The quantification of ERK and p-ERK Western blotting data of the dose-cause; blots were analyzed using the Image J software. D: The quantification of other proteins Western blotting data of the dose-cause; blots were analyzed using the Image J software. E: The quantification of ERK and p-ERK Western blotting data of the time-cause; blots were analyzed using the Image J software.