DKK1 and neoplasm: Proteins of our screening assay cover a wide range of functions, which are revealed by literature research to be related to the estrogen-dependent signaling pathway, such as cell growth (amphiregulin, EGFR) [72,73,74], apoptosis (p53, Bcl-XL, survivin) [75,76], metastasis development (Dkk1, galectin 3, EpCAM, cathepsins) [77,78,79,80], and tumor immunoregulation (IL6, IL8, CCL20) [81,82,83,84].