1 Department of Nephrology, Nara Medical University, 840 Shijo-cho, Kashihara, Nara, 634-8521, Japan. tsuruya@naramed-u.ac.jp.
2 R&D Division, Kyowa Hakko Kirin Co., Ltd., 1-9-2 Otemachi, Chiyoda-ku, Tokyo, 100-0004, Japan.
3 Division of Nephrology, Endocrinology and Metabolism, Department of Internal Medicine, Tokai University School of Medicine, 143 Shimokasuya, Isehara, Kanagawa, 259-1193, Japan.
4 Division of Nephrology, Department of Medicine, Showa University School of Medicine, Namics 301, 4-24-51 Takanawa, Minato-ku, Tokyo, 108-0074, Japan.