Research into the aging process is very new. For many years aging was thought to be the natural and inevitable consequence of a life of wear and tear. The idea that aging could be influenced by the genetic code and had a modifiable biologic component is less than 20 years old. During this time, aging has come to be understood as a complex biologic process controlled by signaling pathways and transcription factors. Similar attitudes pervade the field of nephrology. Whether a decline in renal function with age represents normal aging or kidney disease is the subject of much debate.