APC and neoplasm: The truncated APC can influence the transcriptional activity of β -catenin by at least two different mechanisms: a stimulation of the transcriptional activity of β -catenin upon APC downregulation without any obvious increase of the β-catenin level [44] and alternatively, truncated APC might be required for tumour development independently of its control over the transcriptional activity of β -catenin as previously discussed [45].