The ulcer size evaluated on the microscopic slides as the distance between the desmin-positive muscularis mucosa edges was 1.38 ± 0.22 cm (mean ± standard deviation, n=5) five minutes after the ESD, 1.54 ± 0.23 cm (n=7) one week after the ESD, 0.80 ± 0.14 cm (n=2) three weeks after the ESD, and 0.78 ± 0.11 cm (n=5) eight weeks after the ESD (the pig with steroid injection). This evidence concerns the gene DES and ulcer disease.