Transforming growth factor-beta, or TGFB (see TGFB1, MIM 190180), remains biologically latent after secretion, blocked from activity by its N-terminal propeptide (the latency-associated peptide, or LAP).TGFB is activated by its dissociation from LAP.The latent form of TGFB is secreted in association with a latent TGFB-binding protein, or LTBP (see LTBP1, MIM 150390), and assembled into the extracellular matrix.LTBPs are mainly composed of epidermal growth factor (EGF, MIM 131530)-like repeats and protein domains with 8-cysteine repeats, both of which are also found in fibrillins (e.g., MIM 134797).See Oklu and Hesketh (2000) [PubMed 11104663] for a review of the LTBP gene family.[supplied by OMIM]