Intriguingly, the β-catenin nuclear staining scores and the expression of the 64 targeted genes appear to be less significant in tumours with two-hit APC mutation or one-hit mutation plus inferred allelic loss (Fig. 2b and Supplementary Fig. 2A), suggesting a possible ‘feedback' regulation of WNT activation via non-APC mechanisms in these tumours. Here, APC is linked to neoplasm.