Prion 2025: advancing the understanding and treatment of prion diseases in dialogue with patients and families.

Prion 2025, held in Armação dos Búzios, Brazil (3-7 November 2025), was the first PRION congress in Latin America and brought together 260 participants from 22 countries. Building on the broadening scope of recent meetings, this edition placed the cellular prion protein (PrP) back at centre stage while maintaining a strong focus on prion-like mechanisms and functional amyloids. Clinical and epidemiological sessions addressed rapidly progressive dementias and prion and prion-like diseases, underscoring the need for structured diagnostic pathways and closer interaction between surveillance networks and specialized centres. Basic science sessions explored PrP biology, with an emphasis on liquid - liquid-phase separation, early misfolding events, and structural features that underpin prion propagation and strain diversity. The programme also dedicated space to emerging diagnostics and biomarkers, as well as to therapeutic strategies, including PrP-lowering approaches and targeting proteostasis and cellular clearance pathways. Sessions on yeast, bacterial, and memory amyloids broadened the discussion to functional and evolutionary aspects of amyloid formation. Finally, Prion 2025 strengthened engagement with patient organizations and families, incorporating dedicated panels and family-oriented activities into the programme. Overall, the meeting reinforced links between basic and translational prion research and placed patients' and families' perspectives at the heart of the discussion.