In breast cancer, co-expression of Wnt ligands, including Wnt3, Wnt4, Wnt5a, and Wnt7a, leads to the activation of Wnt pathway [42], while in colorectal cancer, mutation or loss function of the APC gene or protein is more likely to be the reason for Wnt pathway activation [43]. Here, WNT4 is linked to colorectal cancer.