Studies have demonstrated that MMPs and ECE-1 play essential roles in the processing of bigET-1 to ET-1 under various pathological conditions such as aging (Lekontseva et al., 2010), preeclampsia (Ajne et al., 2003; Abdalvand et al., 2013), and hypoxia (He et al., 2007). Here, EDN1 is linked to preeclampsia.