Grb2 regulates the proliferation of hematopoietic stem and progenitors cells.

Although Hematopoietic Stem and Progenitor Cell (HSPC) proliferation, survival and expansion have been shown to be supported by the cooperative action of different cytokines, little is known about the intracellular signaling pathways that are activated by cytokines upon binding to their receptors. Our study showed that Growth factor receptor-bound protein 2 (Grb2) mRNAs are preferentially expressed in HSC compared to progenitors and differentiated cells of the myeloid and erythroid lineages. Conditional deletion of Grb2 induced a rapid decline of erythroid and myeloid progenitors and a progressive decline of HSC numbers in steady state conditions.