TLR4 and serum lipopolysaccharide activity: TLRs are expressed in various types of tissues, including the heart, brain, kidney, liver, lung, small intestine, spinal cord, spleen, and reproductive organs.19 Since among all TLRs, TLR4 is the most expressed protein in the heart, as a potential and significant receptor has been extensively investigated for its critical role in different myocardial inflammatory conditions, including endotoxemia,20,21 myocarditis,22 myocardial infarction (MI),23 ischemia/reperfusion (I/R) injuries,24 heart failure,25 aortic valve diseases,26 atherosclerosis,27 and hypertension.28