Figure 2

Immunohistochemical staining of Ki-67 in the tumour and adjacent tissues (×400). T, centre of the tumour; P1, 0–0.5 cm to the tumour boundary; P2, 0.5–1 cm to the tumour boundary; P3, 1–1.5 cm to the tumour boundary; P4, 1.5–2 cm to the tumour boundary; N, normal mucosa.