 Both have the intrinsic capacity to activate the myogenic factor 5 (Myf5) promoter, a trait only associated with myocytes and this population of brown fat.Progenitors of traditional white fat cells and adrenergically induced brown fat do not have the capacity to activate the Myf5 promoter.Both adipocytes and brown adipocyte may be derived from pericytes, the cells which surround the blood vessels that run through white fat tissue.