Local architecture changes give rise to collective cell behaviors. (A) Graphical representation of a speculative conceptual map of morphodynamic building blocks. Each position represents a distinct local cell architecture within a high-dimensional space, here reduced to two dimensions, where spatial proximity reflects architectural similarity. Green and blue hues represent more mesenchymal architectures, while purple hues indicate structures considered epithelial. Yellow denotes architectures typical of amoeboid cells. (A1) Mesenchymal cells typically exhibit combinations of features found on the left side of the map. (A2) Epithelial cells generally exhibit combinations of features restricted to the right side, although they can exhibit mesenchymal-like traits such as cryptic lamellipodia. (B) Schematic representation of how local cell architectures influence collective behavior. Colors match those in A. (B1 and B2) Composition of local architectures determines single-cell migration behaviors (B2), such as directionality (top row). (B3) Cell–cell contact-based reorganizations—such as CIL—induce local architectural changes (arrow to B1). (B4) These changes generate specific contact-mediated rules, such as retraction upon contact, which in turn modulate individual migration behavior, such as directionality (arrow to B2). (B5) Cumulative effect of these interactions gives rise to characteristic group behaviors, such as space-filling dynamics observed in CIL-driven collectives.