A higher baseline forced vital capacity percentage predicted value (FVC% predicted: OR = 0.98, 95% CI: 0.96 - 0.99) was identified as a protective factor against PPF development.<h4>Conclusions</h4>Patients with CTD-ILD are at high risk of developing PPF, and this progression risk is associated with KL-6, hSP-D, MMP-7, and CA-125. Here, MUC1 is linked to interstitial lung disease.