Uteroglobin (UG) is a steroid-inducible, evolutionarily conserved, multifunctional protein. In terms of molecular structure, regulation and synthesis mechanism, UG, which mediated autocrine and paracrine via its putative receptor, was surmised to be a member of the novel cytokine/chemokine family. Clarification of the structure, regulation and function of UG would contribute to elucidating human common disease, exploring the mystery of embryo implantation and researching the mechanism of oncogenesis.