While it could be said that regenerative medicine is what this journal publishes, that would be cyclical. It could also be claimed that most people interested in the field have a good grasp of what is entailed, and this is probably correct. But, as the field grows and there is a need to carry governments and public opinion along, it is probably worth having a simple explanation of regenerative medicine. And, it is simplicity that is the nub of the matter. There are already a lot of definitions [1–3] but all are lengthy and not the sort of thing scientists, start-ups or advocates can say succinctly when a pharma executive, government minister or member of the public asks for clarification. Here, we address this and the origins and relationships that help to define the field. One of the complications is that regenerative medicine has grown out of a good deal of prior activity. This includes surgery, surgical implants, such as artificial hips, and increasingly sophisticated biomaterial scaffolds. It also draws on hospital procedures such as bone marrow and organ transplants and it relates to tissue engineering. There is no absolute cut-off in the transformation of these into fully developed regenerative medicine but they each leave residues of their input that can mean the patient is not capable of being termed ‘of natural health’with respect to the treated condition. Organ transplants often demand immune-suppressing drugs and metal hips can become loose with time, engineered tissue scaffolds can provoke inflammation and bone marrow sources are variable mixtures that also can be contaminated quite easily by the nature of the cell aspiration procedure. The central focus of regenerative medicine is human cells. These may be somatic, adult stem or embryo-derived cells and now there are versions of the latter cells that have been reprogrammed from adult cells so that both can be conveniently collected under the heading of ‘pluripotent cells’[4, 5]. There appears to be a progression in interest through this sequence. It is driven by the limitations in availability of most specialist somatic cells and the restriction in the expansion of adult stem cells together with their heterogeneity from sources such as bone marrow. Human embryos are not an ideal source from a technical point of view, leaving aside the ethical and moral issues. For this reason, obtaining pluripolent cells in another way is attractive. This progression entails the transfer of genes to human cells [6] and this could bring regenerative medicine and gene therapy closer. Though inevitably the pioneering phase leading towards regenerative medicine has been marked by some failures, there are now sound commercial products for skin ulcer and sports injury damage to the cartilage of the knee [7]. There are also exciting developments with respect to treating patients with bladder dysfunction [8]. These therapies use either autologous or allogeneic somatic cells and, in the case of skin and bladder, the products have a biomaterials component. The outcome of therapy with adult stem cells is at present less clear because the status of these cells is being debated [9], but in the end it will be proof or otherwise of therapeutic outcome that defines their importance.