However, a recent study has shown reduced APC promoter 1A mRNA levels in colorectal tumours with APC promoter 1A hypermethylation although retained APC protein expression through promoter 1B activity, and the authors advocate that even a slight decrease of APC gene transcription through the epigenetic silencing of promoter 1A could have an impact on Wnt signalling, although via unknown mechanisms [33]. This evidence concerns the gene APC and colorectal neoplasm.