Liquid biopsy, a blood-based test that detects and analyses cancer-related biomarkers, is gaining ground as a tool to monitor disease progression and guide treatment decisions. Scientists Catherine Alix-Panabieres and Klaus Pantel, who coined the term in 2010, spoke to ET about its growing role in cancer care, the potential to reduce treatment costs through personalised medicine, and the need for more clinical trials to establish its benefits for patients.