cytokinins are adenine-derived metabolites traditionally characterized as plant hormones and have major roles in plant physiology however they have recently been found in mammals including humans
concentrations in mammalian and human blood are generally 5-10x lower than that seen in plants and appear to be mainly derived from dietary intakes but there may be endogenous production via enzymes such as that from the TRIT1 gene1)
they can also be found in kidneys, heart, and liver
research findings suggest that they may perform important functions, such as in muscle growth, cellular aging processes, or the protection of nerve cells