The discovery of how proteins fold and what happens if they don’t, or do it wrong, has impacted medicine. Protein function and several pathologies depend on folding. Four scientists, Franz-Ulrich Hartl, Arthur Horwich, Kazutoshi Mori and Peter Walter, revealed the role of chaperones in assisting proteins to acquire their correct structure and described a failure warning system, the unfolded protein response (UPR). For their studies, the researchers will receive the 2024 Frontiers of Knowledge Award in Biology and Medicine from the BBVA Foundation.