MAPK7 and major depressive disorder: In the previous study, the Chai Hu formula, like Chai‐Hu‐Shu‐Gan‐San, can treat depression by reversing stress‐induced disruption of ERK1/2 and ERK5 activity, a novel member of the MAPKs family, and is also known as the big MAP kinase, belonging to neuroactive ligand‐receptor interaction [53, 54, 55].