The Galleri¬TM test consists of a single blood test evaluating methylation, rather than mutations, in cell free DNA (cfDNA) to enable pan-cancer screening. DNA sequencing is coupled with a machine learning classifier to report the presence of a cancer (cancer signal detection) and predict cancer signal origin (CSO) for >50 malignancies. Klein et al performed a prospective case-control study to validate the assay and evaluate diagnostic performance. The study included cancer patients (N=2823) and controls (N=1254; confirmed absence of cancer at one year follow-up) aged >20 years, recruited across North America. Results are summarised in Table 1.