sub:provenance {
  beldoc: dce:description "Approximately 61,000 statements." ;
    dce:rights "Copyright (c) 2011-2012, Selventa. All rights reserved." ;
    dce:title "BEL Framework Large Corpus Document" ;
    pav:authoredBy sub:_4 ;
    pav:version "20131211" .
  sub:_3 prov:value "CD4(+) helper T cells can differentiate into several possible fates including: Th1, Th2, T regulatory, and Th17 cells. Although, cytokine production by non-T cells is an important factor in helper T cell differentiation, a characteristic feature of both Th1 and Th2 lineages is their ability to secrete cytokines that promote their respective differentiation. However, cytokines produced by T cells that help to sustain Th17 cells have not yet been identified. Here we show that IL-21 is a product of Th17 cells," ;
    prov:wasQuotedFrom pubmed:17884812 .
  sub:_4 rdfs:label "Selventa" .
  sub:assertion prov:hadPrimarySource pubmed:17884812 ;
    prov:wasDerivedFrom beldoc: , sub:_3 .
}