Corrigendum to “Comparison of the Proliferation and Differentiation Potential of Human Urine-, Placenta Decidua Basalis-, and Bone Marrow-Derived Stem Cells” - Chengguang Wu; Long Chen; Yi-zhou Huang; Yongcan Huang; Ornella Parolini; Qing Zhong; Xiaobin Tian; Li Deng (Stem Cells International)