2 MDD groups: AD-free (N = 15) and AD-treated (N = 15). WB for levels of TLR-4, Hsp60, Hsp70, p-ERK 1/2, p-JNK, p-p38, p38 α/β, I3K, Keap-1, p11,DUSP-2, Nrf-2, NF-κB p65 subunit in cytosol and nucleus of dlPFC neurones. Here, TLR4 is linked to major depressive disorder.