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: In the cohort the cumulative risk of bladder cancer after Wegener ' s granulomatosis , and the relative prevalence of a history of bladder cancer at the time of diagnosis of Wegener ' s granulomatosis , were also estimated .
### Output Text:
In the cohort the cumulative risk of bladder cancer after Wegener ' s granulomatosis , and the relative prevalence of a history of bladder cancer at the time of diagnosis of Wegener ' s granulomatosis , were also estimated . 