Among the 8 candidate biomarkers identified through machine learning, SCPEP1 emerged as the only gene consistently and significantly upregulated in IPF samples across the training dataset (GSE47460) and three independent validation cohorts (GSE150910, GSE213001, and GSE32537) (Figure 5A; Supplementary Figures S2A, D). Here, SCPEP1 is linked to idiopathic pulmonary fibrosis.