Stem cell science, encompassing basic biology to practical application, is both vast and diverse.; a full appreciation of it requires an understanding of cell and molecular biology, tissue structure and physiology, the practicalities of tissue engineering and bioprocessing, and the pathways to clinical implementation—including the ethical and regulatory imperatives that our society requires us to address.; expectation and debate have been driven by the allure of regenerative medicine using stem cells as a source of replacements for damaged or aged tissues.; the potential of stem cell application goes far beyond this.; highly innovative uses of stem cells are emerging as possible therapies for cancers, treating acute damage in conditions such as stroke and myocardial infarction, and resolving a whole range of diseases.