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: We suggest that repeated endothelial injury , including immunologic injury , may be the cause of this lesion both in allografts and native kidneys .
### Output Text:
We suggest that repeated endothelial injury , including immunologic injury , may be the cause of this lesion both in allografts and native kidneys . 