SCAF11 and neoplasm: Analysis of WT and Casp11−/− colons at the 6 week tumour development stage revealed significantly increased IEC proliferation in Casp11−/− colons compared with treatment matched WT colons, as assessed by staining and histological evaluation of the proliferation markers PCNA (Fig. 5c, d) and Ki67 (Fig. 5e, f).