adult stem cell Adult stem cells are undifferentiated cells that reproduce daily to provide certain specialized cells. Until recently it was thought that each of these cells could produce just one particular type of cell. This is called differentiation. However in the past few years, evidence has been gathered of stem cells that can transform into several different forms. BTO:0002666 BrendaTissueOBO adulte Stammzelle multipotent adult progenitor cell somatic stem cell pluripotent stem cell