Nowadays, there are many tools for cancer diagnosis, from imaging techniques to biopsies. In traditional blood tests, liquid biopsy bursts onto the scene as an explosion of possibilities driven by molecular techniques for the detection and sequencing of proteins or genetic material. But specialists are cautious because they know that in liquid biopsies not everything is detected. At the ENA 2022 session “The role of ctDNA in clinical trials,” Marie Morfouace, a translational researcher at the EORTC, presented “ctDNA in clinical trial practice today,” where she described the balance of the possibilities of the liquid biopsy when confronting it with the results in patients offered by the studies published to date.