On the other hand, it is supposed that bFGF acts on MEFs to release supportive factors and to reduce differentiation- inducing activity. It is suggested that that bFGF, at least in part, promotes self-renewal of hES cells by modulating the expression of transforming growth factor b ligands, which, in turn, act on hES cells in autocrine manner. In a most present study, insulin-like growth factor 2 is expressed by autologously derived hES cell fibroblast-like cells in response to bFGF, and alone was sufficient in maintaining hES cell cultures. This study establishes that hdFs produced by hES cells themselves define the stem cell niche of ALK5 Inhibitor II pluripotent human stem cells. The study reveals a previously unappreciated but essential celluar interplay that establishes a paracrine signaling as being required for pluripotency of hES cells. So, it would be possible to establish more effective hES cell culture system by mimicking the stem cell niche for pluripotency. In the present study, we had now investigated the culture of H9 hES cells on a new human Everolimus moa feeder cells��human fetal liver stromal cells. The new feeder cells permitted H9 hES cells prolonged culture in an undifferentiated state. In particular, we had established a transgenic feeder cells��bFGF-hFLSCs that stably express bFGF by lentiviral systems, which could be used to maintain H9 hES cells without any exogenous growth factors. And the bFGFhFLSCs specifically express high levels of bFGF and IGF-2, which are the key factor supports hES cells in culture. And hES cells are successfully maintained feeder-free with conditioned medium of bFGF-hFLSCs. Thus, bFGF-hFLSCs were a novel population that was capable of supporting hES cells expansion more effectively and economically. And also the new culture system could be used as an in vitro model to study comprehensive mechanisms of hES cell self-renewal and pluripotency. There are four FGF receptors. bFGF is related to FGFR1, which accounts for the high affinity of bFGF binding sites in the nucleus and cytoplasm. Previous study suggest that FGF receptors may be important to hES cell culture systems, but are not dominantly expressed by the self-renewing, pluripotent human stem cells. However, IGF1R expression correlates with pluripotent stem cell markers and thereby underscores both the uniqueness and general importance of the IGF-2/IGF1R axis in hES cell lines. So, in the present study, we investigated expression of FGFR1 and IGF1R to confirm the link between bFGF and IGF in the H9 hES cells and hFLSCs culture.