Period circadian protein homolog 3 (PER3)

Originally called a core component of the circadian clock. The circadian clock, an inner time-keeping system, regulates various physiological processes throughout the generation of roughly 24 hour circadian rhythms in gene expression, which can be translated into rhythms in behavior and metabolism.

It is derived from the Latin roots'circa' (about) and'diem' (day) and acts as an important regulator of a wide variety of physiological functions such as metabolism, sleep, body temperature, blood pressure, endocrine, immune, cardiovascular, and renal function. Consists of two major elements: the central clock, residing in the suprachiasmatic nucleus (SCN) of the brain, and the peripheral clocks that are found in virtually every tissue and organ system.