NKX2-3 and anemia (phenotype): This shift in RP vascular patterning is associated with defective extramedullary hematopoiesis manifesting as constitutional anemia under steady-state conditions and repressed stress hematopoietic response and defective megakaryocyte expansion, together demonstrating the complex role of Nkx2-3 in shaping the vascular identity and functionality of RP.