RAB27A and columnar cell hyperplasia of the breast: To assess the role of muscle‐derived sEVs in cognitive protection in CCH rats, we developed an adenoviral vector system encoding Rab27a shRNA to silence Rab27a expression, a known regulator of EV biogenesis and secretion.[56, 57] CCH rats received bilateral intramuscular injections of AAV‐Rab27a‐shRNA to inhibit muscle‐derived sEV secretion (Figure 6B), and successful infection of muscle cells was confirmed (Figure S7H, Supporting Information).