Cover legend: Freeze-fracture view of the apical plasma membrane of an organ of Corti hair cell showing the stereocilia insertions and the lateral margin of the cell. A number of variably sized membrane invaginations and pits, which denote the membrane trafficking machinery for delivery and removal of membrane proteins, are found only at the lateral margin, near the tight junction. Grati et al. (in this issue) study the turnover of a stereocilia membrane protein [Ca²⁺-ATPase isoform 2 (PMCA2)] and show that rapid lateral diffusion of newly delivered proteins mitigates futile cycling of proteins within the trafficking region at the lateral margin of the cell. For more information, see the article by Grati et al. in this issue (pages 6386–6395).