RNPC3 and systemic sclerosis: Almost all patients with SSc-ILD have positive antinuclear antibodies; this can be accompanied by anti-topoisomerase I (anti-Scl-70), anti- Th/To, anti-U3 ribonucleoprotein (RNP), anti- U11/U12 RNP, and rarely anti-centromere antibodies (33).