CD81 and atrial fibrillation: Notably, we found that CD81 was downregulated in both diseases, CKAP4 was consistently upregulated in both diseases, while DPEP2 exhibited a disease-specific expression pattern, downregulated in sepsis and upregulated in atrial fibrillation.To further validate the external generalizability of the model, we constructed predictive models in the external sepsis dataset GSE65682 and the atrial fibrillation dataset.