AKT1 and major depressive disorder: Figure 5a shows ERK as a hub likely to be involved in EC/IC basal differences. Prior research provides ample evidence that ERK plays a role in depression [54], [55]. Figure 5b also identifies ERK as a likely player in IC control vs. stress along with other known key signaling cascades P38 MAPK and PI3K/AKT. These results are also supported by literature demonstrating the importance of these cascades in depression [56], [57].