title: Visual vignette.
authors.affiliation: Chinese Academy of Medical Sciences & Peking Union Medical College Dept. of Endocrinology, Peking Union Medical College Hospital, Shuaifuyuan Road No. 1, Dongcheng District, Beijing, Beijing.
authors.forename: Shi
authors.initials: S
authors.lastname: Chen
authors.affiliation: Chinese Academy of Medical Sciences & Peking Union Medical College Dept. of Endocrinology, Peking Union Medical College Hospital, Shuaifuyuan Road No. 1, Dongcheng District, Beijing, Beijing.
authors.forename: Zi-Qiang
authors.initials: ZQ
authors.lastname: Zeng
authors.affiliation: Chinese Academy of Medical Sciences & Peking Union Medical College Dept. of Endocrinology, Peking Union Medical College Hospital, Shuaifuyuan Road No. 1, Dongcheng District, Beijing, Beijing.
authors.forename: Yu-Xiu
authors.initials: YX
authors.lastname: Li