Each day, tens of billions of cells die and release their DNA into the bloodstream — a quiet biological fact that UCLA researchers have now turned into a diagnostic opportunity. A team there has developed MethylScan, a blood test that reads chemical markers on circulating DNA fragments to detect multiple cancers and organ diseases before they advance, at a cost of under twenty dollars per sample. Rather than searching for mutations, the method listens to a subtler language: methylation patterns that shift when cells become diseased, offering a kind of molecular atlas of the body's hidden distr