TGF β is a cytokine secreted by adipose tissue. Expression of TGF β in adipose tissue correlates with BMI. Diabetes. 2000 Aug;49(8):1374-80. TGF β 1 stimulates release of PAI-1. Mol Med.1997 Jan;3(1):37-48. and suppresses release of Leptin from human adipose tissue. TNF alpha can increase TGF β 1 mRNA expression in adipose tissue of lean mice, while neutralization of TNF alpha or deletion of its receptor in obese mice produces a decrease in TGF β. High TNF alpha levels are recognised in obesity and might be effecting its actions at least to a degree through TGF β?