NUCB1 and major depressive disorder: Based on the published articles, we speculate that both a ZiBuPiYin recipe [53], which was recorded in the book of Bujuji written by Cheng Wu in the Qing dynasty, and Luks-PV [54] which is a pore-forming leukocidin secreted by Staphylococcus aureus, have potential roles in the prevention and treatment of depression because of their reductions in the levels of the NUCB1 protein.