Certain rare gene mutations lead to the activation of the WNT pathway, such as those occurring in the genes axis inhibition protein 1 (AXIN1), axis inhibition protein 2 (AXIN2) and adenomatous polyposis coli (APC) (can only be observed in cases associated with familial adenomatous polyposis) (11). Here, AXIN1 is linked to Familial adenomatous polyposis.