LRRTM4 (AUC = 0.812), PTPN22 (AUC = 0.938), FAM175B (AUC = 0.766), and PROM2 (AUC = 0.852) were identified as core diagnostic markers for distinguishing DCM patients from healthy controls because of their stable differential expression (|log2FC| > 1, FDR < 0.05, Cohen’s d > 0.8) and excellent disease classification performance (Figure 13). This evidence concerns the gene PTPN22 and familial dilated cardiomyopathy.