UCP1 in adipose tissues: two steps to full browning.

The possibility that brown adipose tissue thermogenesis can be recruited in order to combat the development of obesity has led to a high interest in the identification of “browning agents”, i.e. agents that increase the amount and activity of UCP1 in brown and brite/beige adipose tissues. However, functional analysis of the browning process yields confusingly different results when the analysis is performed in one of two alternative steps.