Of note, the MDD responders have a specific pathway activation profile in comparison with controls or the other MDD groups, with the inhibition of immunometabolic pathways, such as the “IL-4 Signalling”, “FAK Signalling”, “T Cell Receptor Signalling”, “G Protein Signalling Mediated by Tubby”, and “Chaperone Mediated Autophagy Signalling Pathway”, and the activation of the “Neuroprotective Role of THOP1 in Alzheimer’s Disease” and of the anti-inflammatory “CTLA4 Signalling in Cytotoxic T Lymphocytes”. This evidence concerns the gene CTLA4 and major depressive disorder.