Immunohistochemical staining was performed on paraffin‐embedded tissue, as described previously 36. Immunostaining for α‐SMA and CD3 was accomplished with the EnVision System (Dako, Glostrup, Denmark). Other markers were identified with the ABC system (Vector Laboratories). The sections were all visualized using 3,3′‐diaminobenzidine (Sigma–Aldrich). CD3‐, CD68‐ and EGFP‐positive cells and the positive areas for α‐SMA, collagen type I, and collagen type III staining were assessed as the average of five randomly selected fields (×200) for each rat with ImageJ software (NIH).