Thus, sex differences and differential expression between proximal and distal colon in Wnt receptor expression and signalling may influence its potential as a therapeutic target [33] Although proximal tumours are more frequent in females, the oestrogen-induced quiescence of Wnt/β-catenin signalling in female CRC [12] will favour normal growth, morphology, and epithelial cell differentiation, whereas a lower activation threshold for Wnt signalling in male CRC will promote cell proliferation, EMT, and tumorigenesis. This evidence concerns the gene FZD1 and colorectal carcinoma.