Although it is generally considered to be a result of neuronal lesions, the discovery that glial cell-specific proteins such as P2RX7, S100 calcium binding protein B (S100B), and GFAP, are involved in the occurrence and progression of depression, especially in those major depression disorder (MDD) patients presenting with suicidal behaviors, as well as the alterative crosstalk of glial cells-neurons exacerbating cell damage, suggests that glial cells play unique roles in specific areas [105,106,107]. Here, S100B is linked to major depressive disorder.