We previously showed that IFN-α and TLR3 activation by poly(I:C) regulates the neuronal expression of a broad set of depression-associated genes in the hippocampus and prefrontal cortex of mice that were also found to be regulated in IFN-α-treated depressed patients and which correlated with depressive behavior in mice [1, 4]. This evidence concerns the gene TLR3 and major depressive disorder.