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:_3 ;
    pav:version "20131211" .
  sub:_2 prov:value "Cigarette smoke is a complex mixture of over 4000 compounds and high levels of oxidants and reactive oxygen species (ROS) have been detected in both mainstream and sidestream smoke. Oxidative stress that ensues, when the antioxidant defences are depleted, is accompanied by increases in ROS production in lung epithelial cells. Cigarette smoke-mediated oxidative stress produces DNA damage" ;
    prov:wasQuotedFrom pubmed:19604067 .
  sub:_3 rdfs:label "Selventa" .
  sub:assertion prov:hadPrimarySource pubmed:19604067 ;
    prov:wasDerivedFrom beldoc: , sub:_2 .
}