About the Authors

Hiroyuki Okada

Contributed equally to this work with: Hiroyuki Okada, Atsushi Tajima

Affiliation Department of Obstetrics and Gynecology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan

Atsushi Tajima

Contributed equally to this work with: Hiroyuki Okada, Atsushi Tajima

Affiliation Division of Molecular Life Science, School of Medicine, Tokai University, Isehara, Japan

Kazuyoshi Shichiri

Affiliation Department of Obstetrics and Gynecology, Tachikawa Hospital, Nagaoka, Japan

Atsushi Tanaka

Affiliation St. Mother's Hospital, Kitakyushu, Japan

Kenichi Tanaka

Affiliation Department of Obstetrics and Gynecology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan

Ituro Inoue

To whom correspondence should be addressed. E-mail: ituro@is.icc.u-tokai.ac.jp

Affiliations Division of Molecular Life Science, School of Medicine, Tokai University, Isehara, Japan , Core Research for Evolutional Science and Technology, Japan Science and Technology Corporation, Kawaguchi, Japan

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

AT, KT, and II conceived and designed the experiments. HO and AT performed the experiments and analyzed the data. AT, KS, KT, and II contributed reagents/materials/analysis tools. HO, AT, and II wrote the manuscript. All authors contributed to editing the manuscript. HO and AT have joint authorship of this manuscript.