One mechanism is the preservation of genomic integrity. Quiescent cells preserve the integrity of their DNA and other cellular components by preventing accumulation of genetic mutations and other damage through autophagy. Quiescent cells also halt their progression by downregulating the expression of cyclins and CDKs to form the cyclin-CDK complex. This maintenance of a reversible arrest allows them to remain in a quiescent state until they receive the cues to re-enter the cell cycle. Quiescent cells also possess the ability to sense and respond to extracellular signals that trigger re-entry into the cell cycle at the right time. This ensures no errors are to be made, and the cell may stay in the G0 phase or re-enter depending on the context at the time.