Fig. 6

Degree of endoscopic submucosal fibrosis in early gastric cancer. (A,B) F0 (no fibrosis), which appears as a blue transparent layer. (C,D) F1 (mild fibrosis), which appears as a white web-like structure in the blue submucosal layer. (E, F) F2 (severe fibrosis), which appears as a white muscular structure without a blue transparent layer in the submucosal layer.