Adrian Harris, MD, DPhil, from the University of Oxford, Oxford, UK, speaks at the 2018 National Cancer Research Institute (NCRI) Cancer Conference, held in Glasgow, UK, about a challenge associated with the treatment of triple negative breast cancer (TNBC). Prof. Harris highlights a challenge in treating those with residual disease after therapy. An approach to understanding the molecular mechanisms underlying TNBC and thus identify targets in individual patients is discussed as a way forward.