A Timeless Link Between Circadian Patterns and Disease.

The Timeless (Tim) gene, originally identified in Drosophila melanogaster and subsequently in mammals, is involved in the molecular clockwork that drives 24h periodicity in physiology and behavior. The Tim protein is involved not only in circadian rhythmicity but also in embryonic development, cell cycle progression, DNA replication, and the DNA damage response (DDR). It is thus a multifaceted factor implicated in the maintenance of many cellular processes, tissue functions, and ultimately homeostasis of various organisms, from insects to humans. This review highlights the current knowledge of Tim functions, especially the most recent achievements, and illustrates the possible roles that this factor plays in the physiological preservation of health, as well as in the pathogenic mechanisms of related diseases.