Our Western blot results showed that Hint1‐KO mice not only under basic conditions but also under chronic immobilization stress exhibited higher expression of BDNF in hippocampus compared with Hint1‐HT mice and their WT littermates, which agreed with the finding that Hint1‐KO mice displayed antidepression‐like behavior, not only under basal conditions but also under CIS. Here, HINT1 is linked to in situ carcinoma.