TLR4 and Anxiety: As to the anxiety‐like behavior, we found that unstressed TLR4‐KO mice spent less time in light area in the LDT compared to unstressed WT mice, which was supported by a recent study in which mice lacking TLR4 had a robust anxiety‐like phenotype (Femenia, Qian, Arentsen, Forssberg, & Heijtz, 2018).