TLR4 and Sepsis: During sepsis, LPS binding to TLR-4 may activate the JNK, ERK, or p38 MAPK pathways or the mitochondria-mediated intrinsic apoptosis pathway, which in turn activates caspase-3, an apoptosis activator effector, and downregulates Bcl-2, an inhibitor of apoptosis [35].