Background
In last decades, obesity became a major health issue worldwide. Processes as well as molecules involved in fat mass regulation remain unresolved up to now. Brown adipose tissue (BAT) is an interesting target to fight obesity, especially since brown adipose tissue in adult humans was recently “rediscovered”. In addition, the occurrence of “brown-like” adipocytes within white adipose tissue (WAT) has also sparked an interest due to potential anti-obese effect. Transforming growth factor-β (TGF-β) superfamily consists of structurally related but functionally diverse cytokines involved in regulation of adipogenesis. Activin receptor-like kinase-7 (Alk7), a member of the TGF-ß family, is highly expressed in adipose tissue. However, its role in adipogenesis, thermogenesis and adipocyte function is not well known.