TTC1 and fibrodysplasia ossificans progressiva: Further, it has been demonstrated that activin A promotes early differential gene expression in ligament fibroblasts from FOP patients, with the activin, TGFβ, and BMP signaling being significantly enriched, and upregulated transcript levels in genes involved in bone metabolism (SHOC2 Leucine Rich Repeat Scaffold Protein (SHOC2), Tetratricopeptide Repeat Domain 1 (TTC1), Tetratricopeptide Repeat Domain 1 (PAPSS2), Dedicator Of Cytokinesis 7 (DOCK7), and Lysyl Oxidase (LOX)) [96].