The largest study to date assessing the use of cell-free DNA (cfDNA) analysis to detect cancer in advance of symptoms has completed enrollment of 140,000 healthy volunteers. The study, being run in the U.K. National Health Service (NHS) by the charity Cancer Research UK (CRUK) and cfDNA diagnostics specialist Grail Inc., is using Grail’s Galleri test to look for cancer-specific methylation patterns in blood.