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Cover Photograph: Upper row Left: Drosophila embryonic epithelium illustrating dynamics of cell boundaries (left top), distribution of a force generator protein (myosin II) (right top), behavior of cell‐cell adhesion molecule (left‐bottom) and junctional tension (right‐bottom). (See Hara pp. 340–350); Middle: In‐silico mechanical assay of epithelial tube using 3D vertex model. The epithelial tube is pinched off as rearranging the multicellular configuration at the stress concentration point. (See Okuda et al . pp. 455–464); A biofilm of Bacillus subtilis . (See Tasaki et al . pp. 369–378). Middle row Left: One of the simplest models that indicate that epithelial cells can migrate within their sheet using only contraction forces acting on cell boundaries. (See Sato pp. 317–328); Middle: Surface topography of a cross‐section of a Xenopus laevis tailbud embryo. Bulges in warm color indicate the area where compressive stress resided before sectioning. (See Murakami et al . pp. 434–443); Right: Four distinctive migration modes were simulated in our mathematical model by changing parameters alpha and beta. These migration modes are observed in actual phenomena. (See Akiyama et al . pp. 471–490). Bottom row: A packing of disks (by green circles) along a Bernoulli spiral lattice, and a Voronoi tessellation (by blue lines) for the same lattice, as geometric models of spiral phyllotaxis such as sunfl ower head. The family of disks can be divided into 3 spirals, 8 spirals, or 11 spirals of contact sequences of disks. The family of Voronoi hexagons also has three types of partitions into 3, 8, and 11 spirals. (See Sushida and Yamagishi pp. 379–387); A model to simulate intra‐ciliary diffusion. The model shows that restricted diffusion of signaling molecules in the cilium results in signal enhancement effect, which may be one of the most important properties of the primary cilium as a signaling center. (See Takao and Kamimura pp. 415–422); Right: The spatial pattern of contractile cells determines the direction of invagination. (See Inoue et al . pp. 444–454).