Expression of STAT3 and PR in decidual cells and the immunoprecipitation of STAT3 with PR-A or PR-B. A) Localization pattern of STAT3 (a, d), phospho-STAT3 (b, e), and PR (c, f) proteins was investigated by immunohistochemistry in uteri of C57BL/6 mice at 5.5 dpc. Nuclei were counterstained with hematoxylin. Arrow indicates embryo. B) Immunoprecipitate with V5 was immunoblotted with PR and STAT3 antibodies. C) Immunoprecipitate with PR was immunoblotted with V5 and PR antibodies. D) Immunoprecipitate with V5 was immunoblotted with PR and STAT3 antibodies.