BAX and atrial fibrillation: Besides, we discovered that overexpression of IRAK1 could notably reverse the downregulation of apoptosis-related proteins (Bax and caspase 3) and the upregulation of mitochondrial fusion-related proteins (MFN1, MFN2, and OPA1), which were mediated by high doses of AF in Ox-LDL-induced HUVECs (Figure 4(b)).