Translationally controlled tumor protein (TCTP) is a multifunctional protein that is involved in immune responses, cell proliferation, cancer progression, and apoptosis . TCTP, also known as histamine-releasing factor (HRF), induces the secretion of histamine that is widely distributed in the brain . Histamine-expressing neurons project to wide areas of the brain, including regions especially important for cognitive functions such as the frontal cortex and hippocampus . Histamine and TCTP are significantly reduced in AD brain compared to age-matched control, suggesting that decreased histamine levels impair cognitive function in AD . Thus, the decreased expression of TCTP might decrease the histamine release and be one of the main causes of dementia.