Until recently, a functional brown adipose tissue was thought to be restricted to rodents and human infants. The last eight years have seen a re-emergence in the presence and activity of brown adipose tissue in adult humans. This study by Shinoda and co-workers1 characterizes the cellular origins and molecular identity of adult human brown adipose tissue. Using RNA sequencing and genome wide expression analysis, the authors characterize that the clonally derived adipocytes isolated from brown fat of adult humans carry the genetic signature of recruitable thermogenic beige adipocytes. They further identify novel molecular markers that were highly enriched in the adult human brown adipocytes and rodent beige adipocytes. This study provides new approaches for BAT research and developing novel BAT targets.