(A) Latent pro-TGF-β (B) Pro-myostatin/GDF8 (C) Pro-activin A (D) Pro-BMP-9 (E) Pro-BMP-9 in complex with ALK1 receptor extracellular domain (F) Latent pro-TGF-β in complex with integrin αVβ6 extracellular domain with the inset showing the details of the interaction between the integrin metal-ion-dependent adhesion site (MIDAS) domain and the RGD motif on pro-TGF-β1 (G). Latent pro-TGF-β in complex with extracellular milieu molecule LRRC32/GARP. The inset showing the details of the interaction between GARP and pro-TGF-β1. The mature domain is in all cases coloured orange and the pro-domains in blue, similar to Figure 1. Other binding proteins are shown in red. Different parts of the pro-domains are labelled for pro-TGF-β1 and pro-myostatin.