Precision oncology offers a hugely exciting opportunity to personalise cancer treatments and prevention for the benefit of the individual but does present great challenges at present, both scientific and ethical. We now have the capacity to identify the abnormalities in genes and proteins that introduce the risk of individuals developing cancer and are responsible for the classical behaviour of a cancer. Having done this, healthcare teams are able to better diagnose cancer, evolve preventive strategies, and develop and deploy targeted cancer therapies. Precision oncology involves better prevention strategies and ensuring that therapeutic interventions can be concentrated on those who will benefit, reducing expense and sparing side effects for those who will not. This new educational resource provides an overview of the latest progress in developing precision oncology, plus a ground breaking collection of case studies ("Problems") showing precision oncology in practice. It includes a clear, readable summary of developments, alongside real-life case studies, providing a valuable update for all involved in the oncology community.