Professor Nicola Valerie, a clinician scientist at The Institute of Cancer Research in the UK, discusses the use of patient-derived cancer models for improving mechanistic understanding and developing new treatments for cancer. Murine and human cancer organoids have been used to identify and validate therapeutic targets for additional research, with 100% negative predictive value and 88% positive predictive value. Future challenges include tissue heterogeneity and the incorporation of the microenvironment.