title: Challenges, progress, and new directions in stem cell therapies: a new section launched in Clinical and Translational Medicine.
authors.affiliation: Stem Cell Institute at James Graham Brown Cancer Center, University of Louisville, 500 S. Floyd Street, Rm. 107, Louisville, KY, 40202, USA. mariusz.ratajczak@louisville.edu.
authors.forename: Mariusz Z
authors.initials: MZ
authors.lastname: Ratajczak
authors.affiliation: Zhongshan Hospital, Fudan University and Shanghai Institute of Clinical Bioinformatics, Shanghai, China. xdwang@fuccb.com.
authors.forename: Xiangdong
authors.initials: X
authors.lastname: Wang