The stromal cell-derived factor 1, also known as C-X-C motif chemokine 12, is a chemokine protein that in humans is encoded by the CXCL12 gene on chromosome 10. It is ubiquitously expressed in many tissues and cell types. From Wikipedia
It demonstrates that intracellular CXCL12 signaling triggers nucleus expulsion, elevating enucleation rates to scale lab-grown blood production.