BAX and atrial fibrillation: Secondly, the results revealed that Ox-LDL stimulation dramatically upregulated apoptosis-related proteins (Bax and caspase 3) and downregulated mitochondrial fusion-related proteins (MFN1, MFN2, and OPA1), while Ox-LDL-mediated changes in the expression of these proteins could also be prominently reversed by AF in HUVECs, especially 100 μM AF (Figure 2(b)).