title: Erratum to: Continuously elevated serum matrix metalloproteinase-3 for 3 ~ 6 months predict one-year radiographic progression in rheumatoid arthritis: a prospective cohort study.
authors.affiliation: Department of Rheumatology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, 510120, People's Republic of China.
authors.forename: Jian-Da
authors.initials: JD
authors.lastname: Ma
authors.affiliation: Department of Rheumatology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, 510120, People's Republic of China.
authors.forename: Xiu-Ning
authors.initials: XN
authors.lastname: Wei
authors.affiliation: Department of Rheumatology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, 510120, People's Republic of China.
authors.forename: Dong-Hui
authors.initials: DH
authors.lastname: Zheng
authors.affiliation: Department of Rheumatology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, 510120, People's Republic of China.
authors.forename: Ying-Qian
authors.initials: YQ
authors.lastname: Mo
authors.affiliation: Department of Rheumatology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, 510120, People's Republic of China.
authors.forename: Le-Feng
authors.initials: LF
authors.lastname: Chen
authors.affiliation: Department of Radiology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, 510120, People's Republic of China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Anatomy and Developmental Biology, Monash University, Clayton, 3800, VIC, Australia.
authors.forename: Jin-Hua
authors.initials: JH
authors.lastname: Li
authors.affiliation: Department of Rheumatology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, 510120, People's Republic of China. liedai2004@163.com.
authors.forename: Lie
authors.initials: L
authors.lastname: Dai