RUNX2 and atrial fibrillation: In addition, the cells pretreated with neutralizing antibodies against BMP-2 (Ab-BMP-2) and BMP-6 (Ab-BMP-6) significantly suppressed the up-regulatory effects of HCS on the gene (Figure 3B) and protein (Figure 3C) expressions of Runx2, osterix, and OPN in AF cells.