{"entity":{"id":"billiontoone","kind":"company","name":"BillionToOne","aka":[],"tldr":"BillionToOne counts DNA molecules in blood far more precisely than standard sequencing. Known first for prenatal testing, it now sells liquid biopsy tests that read a tumour's mutations and track treatment from a blood draw.","summary":"BillionToOne's Quantitative Counting Template technology adds synthetic molecular counters to cell-free DNA sequencing, improving quantitative resolution by more than a thousand-fold according to the company. That platform underlies UNITY prenatal screening and the Northstar oncology line: Northstar Select, a comprehensive liquid biopsy panel for treatment selection in advanced solid tumours, and Northstar Response, which quantifies methylated tumour DNA to monitor response. The company listed on Nasdaq in 2025. It is one of the largest companies to have come out of YC in oncology diagnostics.","asOf":"2026-09-10","links":[{"label":"Y Combinator profile","url":"https://www.ycombinator.com/companies/billiontoone"},{"label":"Official website","url":"https://www.billiontoone.com"}],"tags":["yc"],"related":[],"cancers":[],"sections":["diagnostics"],"technologies":["liquid-biopsy","mrd-testing","cgp"],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"hq":"Menlo Park, CA","country":"US","companyType":"diagnostics","website":"https://www.billiontoone.com","ticker":"BLLN","stage":"public","ycBatch":"S17","investors":["y-combinator"],"funding":[]},"route":"/companies/billiontoone/","neighbours":{"section":[{"id":"diagnostics","kind":"section","name":"Diagnostics & Biomarkers","route":"/fronts/diagnostics/"}],"technology":[{"id":"cgp","kind":"technology","name":"Comprehensive genomic profiling","route":"/technologies/cgp/"},{"id":"liquid-biopsy","kind":"technology","name":"Liquid biopsy (ctDNA)","route":"/technologies/liquid-biopsy/"},{"id":"mrd-testing","kind":"technology","name":"MRD / molecular residual disease testing","route":"/technologies/mrd-testing/"}],"company":[{"id":"y-combinator","kind":"company","name":"Y Combinator","route":"/companies/y-combinator/"}]}}