Biology and postnatal development of organ systems of cynomolgus monkeys (Macaca fascicularis).

Background: The cynomolgus macaque has become the most used non-human primate species in nonclinical safety assessment during the past decades.

Methods: This review summarizes the biological data and organ system development milestones of the cynomolgus macaque available in the literature.

Results: The cynomolgus macaque is born precocious relative to humans in some organ systems (e.