For decades, scientists have focused on amyloid beta as a major culprit behind Alzheimer’s disease, spending billions of dollars developing treatments that have often delivered disappointing results. Now, researchers at UC Santa Cruz are drawing attention to a largely overlooked peptide called P3 that could also play a role in the disease. Previously believed to be harmless, P3 can form harmful-looking protein clumps even faster than amyloid beta and may also damage brain cells.