title: Reply to Dr. Witwer's letter to the editor.
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, Advanced Institute of Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing University, Nanjing, Jiangsu 210093, China.
authors.forename: Hongwei
authors.initials: H
authors.lastname: Liang
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, Advanced Institute of Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing University, Nanjing, Jiangsu 210093, China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Fu
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, Advanced Institute of Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing University, Nanjing, Jiangsu 210093, China.
authors.forename: Xi
authors.initials: X
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, Advanced Institute of Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing University, Nanjing, Jiangsu 210093, China. Electronic address: kzen@nju.edu.cn.
authors.forename: Ke
authors.initials: K
authors.lastname: Zen
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, Advanced Institute of Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing University, Nanjing, Jiangsu 210093, China. Electronic address: cyzhang@nju.edu.cn.
authors.forename: Chen-Yu
authors.initials: CY
authors.lastname: Zhang
mesh_terms: D006801:Humans; D035683:MicroRNAs / Q000097:blood*; D010944:Plants / Q000235:genetics*; D018749:RNA, Plant / Q000097:blood*
chemical_list: D035683:MicroRNAs; D018749:RNA, Plant