In this context, NT-proBNP is inexpensive and appeared to be a good indicator of cardiac overload/distress, although it is not specific only for left ventricular systolic dysfunction, since it could be elevated in diastolic left ventricular dysfunction or pulmonary disease leading to pulmonary hypertension and right ventricular dysfunction. The gene discussed is NPPB; the disease is pulmonary arterial hypertension.