Receptor for TNFSF12/TWEAK (By similarity). Weak inducer of apoptosis in some cell types. Promotes angiogenesis and the proliferation of endothelial cells. May modulate cellular adhesion to matrix proteins. Associates with TRAF1 and TRAF2, and probably also with TRAF3. Highly expressed in fetal heart, intestine, kidney, liver, lung and skin, and in adult heart and ovary. Intermediate expression in adult kidney, lung and skin. By FGF-1.