Compared with the AR group, the data of the Tet2−/−AR group were also significantly different, reflecting that the corresponding depressive symptoms were further aggravated, indicating that Tet2 was involved in the depression-like behavior of AR mice, and the absence of Tet2 would lead to the aggravation of depression-like behavior of AR mice (Fig. 2J, K). This evidence concerns the gene TET2 and major depressive disorder.