Abstract
A view that guides the bulk of cancer research and oncology posits that each neoplastic cell in a tumor is a genetic offspring of another neoplastic cell. Yet, analyzing tumors from transplant patients has revealed that some normal migratory cells adopt the phenotype of neoplastic cells without acquiring their genome, thus becoming what I suggest to call adopted neoplastic cells. This commentary reviews the evidence for the existence of adopted neoplastic cells, outlines the consequences of their presence, and discusses what kind of cells can be adopted, how, and why.