Summary

Hematopoietic stem cells transplantation has been wildly used in clinical settings and has shown exciting results in treating a wide variety of diseases. However, the relative small number of hematopoietic stem cells in bone marrow, even lower in peripheral or umbilical cord blood limits its clinical utility. There are several protocols, which have been developed to expand hematopoietic stem cells to reach clinical goal. With the recent insights into the mechanisms of hematopoietic stem cells self-renewal, we postulate that Cdx4, which is coded by one of the caudal related homeobox genes and regulates the expression of hox genes, could fuse with protein transduction domains, thereby get the ability to cross cellular membrane. And the recombinant fusion proteins could be used in expanding hematopoietic stem cells. Meanwhile, Cdx4 fusion proteins would be more efficient than other methods that had been developed for it can up-regulate a cocktail of hox genes, which has been proved to be capable of amplifying hematopoietic stem cells. It would provide us an alternative protocol to amplify hematopoietic stem cells if the hypothesis proved to be practical.