Catherine Alix-Panabieres, PhD, University Medical Center of Montpellier, Montpellier, France, outlines the different circulating biomarkers defining liquid biopsy today. These circulating biomarkers include circulating tumor cells (CTCs), circulating tumor DNA (ctDNA) and exosomes. The clinical utility of these new biomarkers is still under investigation. However, Dr Alex-Panabieres emphasises the importance of CTCs in comprehending the metastatic cascade. This interview took place at the American Association for Cancer Research (AACR) Annual Meeting 2022 in New Orleans, LA.