EDNRA and systemic sclerosis: Serum ET-1 was also found to correlate with the echocardiographic parameters of right ventricular overload, which is considered a noninvasive indicator of right ventricular dysfunction in SSc patients [74]; while in SSc patients with SRC, several studies showed raised levels of ET-1 and increased expression of ETAR and ETBR [75,76,77].