tokens: In early Xenopus embryos , the transforming growth factor-beta member activin induces the gene Mix .2 by stimulating the formation of a multiprotein complex , activin responsive factor ( ARF ) .
folded_tokens: in early xenopus embryo , the transform growth factor-beta member activin induce the gene Mix .2 by stimulate the formation of a multiprotein complex , activin responsive factor ( arf ) .