Figure 3. Identification of core genes and construction of a biomarker panel for the diagnosis of CD and RA. (A) Graph depicting the best LASSO model parameters and coefficients in the CD discovery cohort. (B) Graph depicting the best LASSO model parameters and coefficients in the RA discovery cohort. (C) Venn diagram displaying core genes in the CD and RA discovery cohorts. (D) Differential expression analysis of five core genes in the CD discovery cohort. (E) ROC analysis and AUC calculation for determining the diagnostic utility of a biomarker panel consisting of the five core genes in CD. (F) Differential expression analysis of five core genes in the RA discovery cohort. (G) ROC analysis and AUC calculation for determining the diagnostic utility of a biomarker panel consisting of the five core genes in RA. Abbreviations: LASSO: least absolute shrinkage and selection operator; CD: Crohn’s disease; RA: rheumatoid arthritis; ROC: receiver operating characteristic; AUC: area under the curve. **P < 0.01; ****P < 0.0001.