In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: The co - administration of aspirin with N - [ 4 - ( 5 - nitro - 2 - furyl ) - 2 - thiazolyl ] - formamide ( FANFT ) to rats resulted in a reduced incidence of FANFT - induced bladder carcinomas but a concomitant induction of forestomach tumors .
### Output Text:
The co - administration of <span class="chemical">aspirin</span> with <span class="chemical">N - [ 4 - ( 5 - nitro - 2 - furyl ) - 2 - thiazolyl ] - formamide</span> ( <span class="chemical">FANFT</span> ) to rats resulted in a reduced incidence of <span class="chemical">FANFT</span> - induced bladder carcinomas but a concomitant induction of forestomach tumors . 