UCP1 and pheochromocytoma: Until 2009, the widely held view was that BAT (or thermogenic adipocytes) is absent from adult humans, despite anatomical studies identifying multi-locular adipocytes (Heaton, 1972), and more critically: (i) UCP1 being identified in adipose tissue depots of adults, including elderly subjects (Lean et al., 1986a), (ii) activation of BAT being demonstrated in phaeochromocytoma patients (Ricquier et al., 1982; Lean et al., 1986b), and (iii) UCP1 gene expression in adipose tissue of adults, particularly in phaeochromocytoma (Bouillaud et al., 1988).