EDN1 and neoplasm: Engagement of ETA-receptor by ET-1 triggers tumorigenesis and tumour progression by activation of tumour proliferation, invasion, angiogenesis, and inhibition of apoptosis (Pedram et al, 1997; Bagnato and Catt, 1998; Bagnato et al, 1999; Eberl et al, 2000b; Salani et al, 2000; Rosano et al, 2001; Del Bufalo et al, 2002).