TGFB1 and focal segmental glomerulosclerosis: 2,3 Although, the role of TGF-β1 in the pathogenesis of glomerulosclerosis and renal fibrosis in patients with podocytopathies, such as focal and segmental glomerulosclerosis (FSGS) has been demonstrated, the signalling is also activated in proliferative GN, and correlates with the severity of inflammation.