The State Key Laboratory of Pharmaceutical Biotechnology and Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, NJU Advanced Institute for Life Sciences (NAILS), School of Life Science, Nanjing University, Nanjing 210093, China Department of Bioinformatics, Medical School, George August University of Gxc3xb6ttingen, Goldschmidtstrasse 1, Gxc3xb6ttingen D-37077, Germany.