Stimulation of TLR4 using heat-inactivated Escherichia coli has been shown to activate the p38 MAPK and ERK1/2 signaling pathways, leading to adhesive, migratory, and metastatic behavior of non-small cell lung cancer (NSCLC) cells in vivo (Chow et al., 2015). Here, TLR4 is linked to non-small cell lung carcinoma.