ERK/MAPK signaling pathway mediates the effects of TGF-β on biological behavior of ESCs. TGF-β plasmid-transfected ESCs were treated with U0126 (MAPK/ERK1/2 inhibitor; 5 µM). (A) MTT assay in different groups. (B) ESCs successfully migrating to the lower surface in different groups. Scale bar, 100 µm (C) Number of ESCs successfully migrating to the lower surface in different groups. (D) ESCs successfully invading the lower chamber in different groups. Scale bar, 100 µm. (E) Number of ESCs successfully invading the lower chamber in different groups. Data are presented as the mean ± standard error of the mean, and this procedure was performed in triplicate. *P<0.05, **P<0.01 vs. vector group, #P<0.05, ##P<0.01 vs. TGF-β group. ERK, extracellular signal-regulated kinase; MAPK, mitogen-activated protein kinase; TGF, transforming growth factor; ESC, endometrial stromal cell.