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: After 12 wk , the inulin clearance was higher in rhIGF - I - treated rats , 0 . 48 + / - 0 . 08 versus 0 . 24 + / - 0 . 06 mL / min / 100 g of body weight in untreated PAN nephropathy animals , p < 0 . 05 .
### Output Text:
After 12 wk , the inulin clearance was higher in rhIGF - I - treated rats , 0 . 48 + / - 0 . 08 versus 0 . 24 + / - 0 . 06 mL / min / 100 g of body weight in untreated <span class="chemical">PAN</span> nephropathy animals , p < 0 . 05 . 