**4.2.3 Obtaining HSC from induced pluripotent stem cells**

Differentiation of iPSC into hematopoietic lineage have been achieved using a combination of specific cytokines and growth factors (Sakamoto et al., 2010) and have already demonstrated from both mouse and human iPSC (Lengerke et al., 2009; Niwa et al., 2009; Woods et al., 2011). However, the number of cells obtained in view of therapeutic use is still insufficient and small molecules that might expand the production of hematopoietic cells have yet to be found. Studies in this direction are beginning to emerge. For example, Wnt signaling, in particular WNT3a, mediates the stimulation of hemoangiogenic cell development and increase hematopoietic differentiation from ESC and iPSC (Wang and Nakayama, 2009; Wang et al., 2010). However, the conditions to generate human HSC capable of robust, long-term, multilineage engraftment from iPSC are still hoped for.
