Between the genome and the body's lived experience lies a layer of molecular instruction that science is only beginning to read clearly. A new review in Genes & Diseases illuminates how a chemical mark on RNA—known as m6A—governs the brain's construction and upkeep, and how environmental toxins such as manganese and arsenic corrupt this governance in ways that may seed Alzheimer's, Parkinson's, and epilepsy. The discovery reframes a long-standing question: it is not only what poisons do to our genes, but how they alter the way our cells interpret those genes, that may determine the fate of the