FZD6 and colorectal carcinoma: By analysis of the expression pattern of FZDs and NPTX2 in GEO dataset (GSE6988), including normal colon tissue, CRC tissue, and liver metastasis, we found only FZD6 exhibited a similar expression pattern as NPTX2, which is gradually increase from normal colon tissue, CRC tissue to liver metastasis (Fig. 5a, b and Fig. S5A).