Additionally, the down-regulation of phosphorylated SMAD2/3, phosphorylated NF-κB, phosphorylated ERK1/2, and phosphorylated JNK also proved to be crucial indicators of the improvement of depression symptoms (Dow et al., 2005; Su et al., 2017; Zhang et al., 2017b). Here, MAPK8 is linked to depressive disorder.