Table 2.

Niche-secreted factors regulating HSC quiescence

Factor	Source	Effect on HSC quiescence	Reference
CXCL4	Megakaryocytes and plateles	Preserving quiescence	[207, 210]
CXCL12	LepR+ stromal cells	Preserving quiescence	[208, 209]
TGF-β	Megakaryocytes and Schwann cells	Preserving quiescence	[211, 212]
Thrombopoietin	Osteoblasts	Preserving quiescence	[213, 214]
Osteopontin	Osteoblasts	Preserving quiescence	[215]
Angiopoietin-1	Osteoblasts	Preserving quiescence	[216]
Prostaglandin E2	Macrophages	Preserving quiescence	[217]
Histamine	Myeloid cells	Preserving quiescence	[219]
Adiponectin	Adipocytes	Inducing quiescence exit	[225]
Leptin	Adipocytes	Inducing quiescence exit	[227]
IGF1	Hepatocytes and osteoblasts	Inducing quiescence exit	[228]