Table 1. Antibodies and antigen retrieval conditions used in this study.

Marker	Antibody clone	Dilution/final concentration	Antigen retrieval	Source
Ki67	MIB-1	1 : 50	0.01 M sodium citrate buffer	Dako, Copenhagen, Denmark
AE1/AE3	AE1/AE3	1 : 100	0.01 M sodium citrate buffer	Dako
Collagen IV	COL-94	1 : 500	0.01 M sodium citrate buffer	Sigma, Poole, UK
αvβ6	6.2A1	0.5 μg ml–1	Proteinase K	Generated as described in Weinreb et al (2004)