Jenny Seligmann, MBChB, PhD, University of Leeds, Leeds, UK, provides an overview of the lessons learnt from the molecularly stratified FOCUS4 trial (EudraCT Number: 2012-005111-12), which assessed either capecitabine (FOCUS4-N), or adavocertib (FOCUS4-C) in patients with metastatic bowel cancer. Dr Seligmann highlights how many aspects of the trial have changed over time, including how the patients were stratified, as well as the importance of progression free survival (PFS) as a primary endpoint. This interview took place at the National Cancer Research Institute (NCRI) Festival 2021.