Protein turnover is the process by which proteins in cells are continuously being synthesized and degraded, in order to maintain the proper balance of proteins in the cell. This process is crucial for regulating various cellular functions, such as cell growth, differentiation, and response to stress. Protein turnover is tightly controlled by a complex network of mechanisms, including protein degradation pathways such as the ubiquitin-proteasome system and autophagy. Understanding protein turnover is important for studying various biological processes, as well as for developing potential therapeutic strategies for diseases related to protein misfolding and aggregation.