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 this case , the authors postulate that the use of estradiol and progesterone and the underlying DM increased vascular thrombogenicity , which provided a common denominator for thrombosis of both the ICA and the venous sinus .
### Output Text:
In this case , the authors postulate that the use of <span class="chemical">estradiol</span> and <span class="chemical">progesterone</span> and the underlying DM increased vascular thrombogenicity , which provided a common denominator for thrombosis of both the ICA and the venous sinus . 