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:_5 ;
    pav:version "1.4" .
  sub:_4 prov:value "Whether this model represents an accelerated version of normal cancer progression, or simply a bypass of the premalignant stages, is still unclear. Human tumours that bypass premalignant stages have not been described. The importance of the angiogenic switch was also recently demonstrated by Weinberg and colleagues55. They showed that expression of the SV40 early region, TERT and activated RAS were sufficient to transform primary epithelial cells in vitro. However, the ability to grow in vivo depended on the level of HRAS expression - cells that expressed low levels of RAS were dormant and non-angiogenic, whereas cells that expressed high levels of RAS developed into full-blown tumours." ;
    prov:wasQuotedFrom pubmed:12778130 .
  sub:_5 rdfs:label "Selventa" .
  sub:assertion prov:hadPrimarySource pubmed:12778130 ;
    prov:wasDerivedFrom beldoc: , sub:_4 .
}