Some evidence indicates that transforming growth factor (TGF)-β plays a key role in the vascular remodeling (7, 9, 28–30); and, in Sch-PAH, the release of this cytokine is probably a consequence of the Th2 inflammation elicited by eggs deposited into lungs through a series of cellular and signaling events (7, 9, 29). The gene discussed is TGFB1; the disease is pulmonary arterial hypertension.