In confluent epithelial monolayers, tricellular junctions (tTJs) are assembled at vertexes where three cells meet. In article number 2001213, Dimos Poulikakos, Aldo Ferrari, and co‐workers establish the junctional maturity at tricellular contacts as a descriptor of epithelial jamming and unjamming transitions. During tissue maturation, wound healing, or in response to osmolarity changes, epithelial cells collectively adapt their shape and motility along with the modulation of tTJs maturity. [Image: see text]