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: Podocyte injury and focal segmental glomerulosclerosis have been related to mToR inhibition in some patients , but the pathways underlying these lesions remain hypothetic .
### Output Text:
Podocyte injury and focal segmental glomerulosclerosis have been related to mToR inhibition in some patients , but the pathways underlying these lesions remain hypothetic . 