The article by Eldar and Elowitz discusses the essential role of noise in genetic circuits, which are responsible for regulating cellular functions. Noise, often seen as a nuisance, is found to be crucial in various cellular activities, including gene expression, probabilistic differentiation, and evolutionary transitions. The authors review the types of dynamic behaviors enabled by noise and their functional roles in cells. They highlight three main areas where noise plays a significant role: gene expression coordination, probabilistic differentiation, and evolutionary adaptation. In gene expression, noise is characterized by bursty production of proteins and time averaging, which helps buffer protein concentration. Noise can enable coordinated regulation of large sets of genes and probabilistic differentiation strategies across cell populations. In evolutionary contexts, noise can facilitate the evolution of new traits and qualitative changes in development. The article also addresses the challenges and future directions in understanding the functional roles of noise in genetic circuits.The article by Eldar and Elowitz discusses the essential role of noise in genetic circuits, which are responsible for regulating cellular functions. Noise, often seen as a nuisance, is found to be crucial in various cellular activities, including gene expression, probabilistic differentiation, and evolutionary transitions. The authors review the types of dynamic behaviors enabled by noise and their functional roles in cells. They highlight three main areas where noise plays a significant role: gene expression coordination, probabilistic differentiation, and evolutionary adaptation. In gene expression, noise is characterized by bursty production of proteins and time averaging, which helps buffer protein concentration. Noise can enable coordinated regulation of large sets of genes and probabilistic differentiation strategies across cell populations. In evolutionary contexts, noise can facilitate the evolution of new traits and qualitative changes in development. The article also addresses the challenges and future directions in understanding the functional roles of noise in genetic circuits.