CKAP4 and atrial fibrillation: In the selection of feature genes for atrial fibrillation, LDHB, DPEP2, BCL11B, CKAP4, RORA, PFKFB2, and CXCR4 were identified as potentially important predictors, with the model error being lowest when the number of genes reached eleven (Fig 3C, 3D).