Stochasticity (or noise) at cellular and molecular levels has been observed extensively as a universal feature for living systems. However, how living systems deal with noise while performing desirable biological functions remains a major mystery. Regulatory network configurations, such as their topology and timescale, are shown to be critical in attenuating noise, and noise is also found to facilitate cell fate decision. Here we review major recent findings on noise attenuation through regulatory control, the benefit of noise via noise-induced cellular plasticity during developmental patterning, and summarize key principles underlying noise control. 2 Nie Q et al. Sci China Math studies investigate how to control or utilize noise in living systems [7,10,[10][11][12][13][14][15][16][17][18]. While noise may induce heterogeneity within the cell population, contributing to diversity in cell fate choice [19][20][21], it usually causes uncertainty in information transmission in the cell and impairs robustness of cellular functions, which is one of the main reasons for the difficulty in robust circuit functions [4,22]. A natural question at hand is how cells deal with noise effectively.Since cellular functions, such as bistability, oscillation and adaptation, have been found to link to regulatory network architectures [23], the network property is naturally important in noise control [18,[24][25][26][27][28][29][30][31]. What are basic constraints on the regulatory networks for noise attenuation? How noise is controlled in function-specific systems, such as adaptive systems or oscillatory systems? In addition, can noise be utilized to achieve specific biological functions? How does noise affect spatial organization and morphogen-mediated patterning? How can a precise and robust readout be generated from the noisy spatial morphogen gradient?In this work, we first review major noise attenuation mechanisms in regulatory networks, and then explore key strategies to combat noise in morphogens during spatial patterning. We conclude by summarizing the major mechanisms in noise control.