Highlights from the Susan Lindquist School on Proteostasis— EMBO | FEBS Lecture Course, 16–19 September, 2025, Espoo, Finland

The maintenance of protein homeostasis is a fundamental premise for the survival of all life. The synthesis, folding, localization, and degradation of thousands of proteins must be organized according to various conditions. To ensure such a stable and functional proteome, the proteostasis network evolved. Dedicated to this, the fourth School on Proteostasis, a co-funded EMBO|FEBS Lecture Course in memory of Susan Lindquist, took place in Espoo, Finland on 16-19 September 2025, with 59 early career researchers (PhD students or postdoctoral fellows), 18 leading scientists, and two editors attending and discussing the current state of the field. From basic principles to the latest therapeutic developments, this meeting provided a comprehensive overview of proteostasis. This report summarizes the lecture course and highlights selected presentations.