LYPD1 and interstitial lung disease: In support of these results, serum LYPD1 levels showed no correlation with Krebs von den Lungen-6 (KL-6) (r = 0.001335, p = 0.9944) nor surfactant protein D (SP-D) (r = 0.05338, p = 0.7873), both of which are well-known serological markers of ILD19 including SSc-related ILD (SSc-ILD)20 (Fig. 2C,D).