The Bloodwise Childhood Leukaemia Cell Bank is a national collection of samples from children and young people with paediatric haematological malignancies. It is very well annotated with demographic, clinical and genetic features. This annotation enables identification and curation of very rare subgroups. There is a range of sample types including viable cells and DNA from bone marrow, plasma and CSF supporting many different types of project. The Bank is open to international as well as UK-based researchers where at least one of the investigators is based at a UK university or NHS institution. Applications are reviewed rapidly by an independent review panel. Our team can give help and advice at all stages of the application from initial enquiry to dispatch of samples. The Bank also holds a collection of HLA typed cord blood which are subject to the same review process.