Negative regulator of the Wnt signaling pathway. Inhibits Wnt signaling in a cell-autonomous manner and functions upstream of beta-catenin. May act via its interaction with Wnt and LRP proteins. May play a role in colorectal tumorigenesis. Homodimer. Interacts with LRP5 and WNT3A. Abundantly expressed in heart, pancreas, prostate and ovary. Moderately expressed in lung, liver, kidney, spleen, thymus, colon and peripheral lymphocytes. Abundantly expressed in both the epidermal and dermal compartments of the hair follicle. Present in scalp skin Highly expressed in the hair follicle dermal papilla, the matrix, and the hair shaft (at protein level). Target gene of the Wnt/Beta-catenin pathway, transcriptionally regulated by the CTNNB1/TF7L2 complex. N-Glycosylated. The disease is caused by variants affecting the gene represented in this entry. Belongs to the APCDD1 family. Truncated N-terminus. Truncated N-terminus.