NPPB and systemic sclerosis: In systemic sclerosis, sensitive and specific, validated biomarkers are not confirmed yet, despite of the overwhelmed and extensive research, except for the NT-pro-brain natriuretic peptide (NT-proBNP) in pulmonary arterial hypertension, the anti-topoisomerase (anti-Scl70) in dSSc, and the anti-centromere antibody in lSSc.