IGFBP2 and atrial fibrillation: As shown in the box plot (Figure 2A) and heatmap plot (Figure 2B), we noticed that the expression levels of RBM15B, IGFBP2, IGFBP3 and ALKBH5 were significantly increased, while the expression levels of HNRNPC and HNRNPA2B1 were significantly decreased in AF samples compared with SR samples.