CKAP4 and atrial fibrillation: Ultimately, by taking the intersection of the results from the three machine learning methods, we identified six feature genes in sepsis: CD81, CLU, GLRX, CKAP4, DPEP2, and BCL11B (Fig 3M); and seven feature genes in atrial fibrillation: LDHB, CD81, PFKFB2, CKAP4, CXCR4, DPEP2, and RORA (Fig 3N).