SFTPD and interstitial lung disease: For SSc-related ILD, it has been reported that high levels of anti-U11/U12 antibodies, human epididymis protein 4, secreted frizzled receptor protein 4, transcription factor scleraxis, endothelin-1, cold-inducible RNA-binding protein, Krebs von den Lungen-6, surfactant protein D, CA15-3, and intercellular adhesion molecule 1 were potential serum biomarkers for early detection and severity assessment of ILD [15–22].