Table 2.

A comparison of iron regulation in normal, untranfused, and transfused β-thalassemia major.

Condition	Erythropoiesis	GDF15	Hepcidin	Iron absorption
Normal	Normal	Normal	Increases when the iron body level increases or with inflammation	Decreases
			Decreases with iron deficiency or hypoxia	Increases
Untranfused β-thalassemia major	Increased IE	Increases	Decreases	Increases
Transfused β-thalassemia major (regular transfusion)	Decreased IE	Decreases	Increases	Decreases

GDF15 = growth differentiation factor 15; IE = ineffective erythropoiesis.