Anterior Gradient Protein 2(AG-2) and Anterior Gradient Protein 3 (AG-3) are human homologues of genes involved in differentiation, are associated with oestrogen receptor-positive breast tumours and interact with metastasis gene C4.4a and dystroglycan (hAG-3 protein). AG-3 could serve as a prognostic marker for survival in patients with low grade and high grade serous ovarian carcinomas.