TLR4 and cancer: With regards to the cell death-related signaling pathways, TLR4 activation has been reported to lead to apoptosis in neuronal cells, in various types of cancer cells including lung cancer and THP-1 cells through reactive oxygen species (ROS) production, as well as activation of both extrinsic (including mainly caspase-8 cleavage) and intrinsic apoptotic pathways (mitochondrial-dependent pathway resulting in caspase-9 cleavage) [17, 22–24].