TLR4 and cancer: Expression or upregulation of TLR4 has been identified in tumor cells, and although it is not always the case (Lamrani et al., 2016), TLR4 activation is mostly reported to stimulate cancer cell aggressive behavior (Molteni et al., 2006; Ikebe et al., 2009; Liao et al., 2012; Chung and Kim, 2016; Sun et al., 2016).