[Term] id: PR:000000099 name: inhibitory smad protein def: "A smad protein that is an antagonist of the transforming growth factor beta (TGF-beta) superfamily signaling pathways. It lacks the C-terminal SSxS motif, necessary for receptor mediated phosphorylation that is present in the receptor-regulated smads." [PMID:11532220] comment: Category=family. xref: PIRSF:PIRSF500412 is_a: PR:000000027 ! smad protein