School of Medicine, Tsinghua University, Beijing, China 100084.|School of Medicine, Tsinghua University, Beijing, China 100084.|School of Medicine, Tsinghua University, Beijing, China 100084.|School of Medicine, Tsinghua University, Beijing, China 100084.|School of Medicine, Tsinghua University, Beijing, China 100084.|School of Medicine, Tsinghua University, Beijing, China 100084.|School of Medicine, Tsinghua University, Beijing, China 100084.|School of Medicine, Tsinghua University, Beijing, China 100084.