Thanks to scientists like Pierpaoli and Regelson, as well as many of their colleagues all over the world, today we know considerably more about the pineal gland and its "miraculous" hormone melatonin. During more than three decades of extensive research in senescence, endocrinology, and immunology, they consistently came across this particular organ and its secretion. Finally they came to the conclusion that they had found "the controller of all controllers".

The pineal body "rules" our entire endocrine gland system throughout our whole life, which in turn produces hormones which control all our bodily functions. As an "intelligent" gland, it does the right thing at the right time to control all the other glands in our organism, which affects the activities of every single cell in our body. By doing this it rules functions like:
· development and growth of the body,
· reproduction,
· body temperature control,
· proper kidney function,
· the body's sleep-wake-cycle,
· control of the immune system,
· stress-control (destruction of substances causing stress, e.g. corticosteroids as produced by the suprarenal glands),
· protection of cellular DNA against attacks from viruses or carcinogenic vectors,
· destruction of "free radicals" - aggressive molecules with a free oxygen atom, which may severely damage the cell membranes and cause the development of cancer - as one of the most powerful "anti-oxidants",
· cellular energy production, and control of the energy flow through the whole organism by transforming the thyroid hormone T4 into the highly energetic hormone T3.
Melatonin is a "condition-dependent" hormone, and therefore affects all organs of the body. Its main task is to control the blood-levels of all other hormones and to maintain their homeostasis, thus supporting them in their respective functions. Changes in the melatonin level cause the levels of other hormones to change also.

Furthermore, Pierpaoli and Regelson discovered that a normal melatonin level also ensures that the immune system detects and immediately destroys "aggressive vectors", germs, or viruses. As one of the most powerful anti-oxidants, melatonin is also very effective in neutralising so-called "free radicals", which are known to be responsible for the generation of cancer cells. Melatonin, which can cross all barriers to enter every cell, "is the best free radical scavenger known," Russel J. Reiter contends. Moreover, specific oncological investigations have shown that melatonin can also support and enhance certain chemo-therapeutical medicines, and at the same time reduce their sometimes very harmful side effects to within tolerable levels.

The most significant contribution of Regelson and Pierpaoli, however, seems to be their discovery that the pineal body controls the process of ageing, with melatonin as its agent, and thus actually represents what scientists have been looking for for many generations: the "Clock of Ageing".