Introduction:
Noise serves functional roles in biology across different scales, contrary to intuition. At the micro-scale, biased Brownian motion of the Myosin head over the Actin filament results in muscle contraction1,2. At the macro scale, intrinsic variations in velocity and direction among individual fishes bring about collectivity in fish schooling3. At the intermediate mesoscale heterogeneity in the position and alignment of ciliated cells in the lung tissue facilitates optimal ciliary flow clearance4. Biological tissues display heterogeneity in terms of biochemical and mechanical processes within the cells5. Part of this heterogeneity is deterministic, such as variations arising from cellular differentiation into distinct cell types6–9. However, a lot of biological heterogeneity is observed as stochastic noise10–14. While the role of deterministic heterogeneity in tissues is intuitive, stochastic heterogeneity is often characterized as noise15 and the physiological relevance of this noise remain largely elusive. We explore the relevance of stochastic heterogeneity in epithelial function in the following section.