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: RESULTS : The main pathologic diagnoses ( some overlap ) were acute rejection ( AR ; n = 4 ) , chronic rejection ( CR ; n = 5 ) , AR + CR ( n = 4 ) , recurrent IgA nephropathy ( n = 5 ) , normal findings ( n = 2 ) , minimal - type chronic FK506 nephropathy ( n = 9 ) , and mild - type FK506 nephropathy ( n = 11 ) .
### Output Text:
RESULTS : The main pathologic diagnoses ( some overlap ) were acute rejection ( AR ; n = 4 ) , chronic rejection ( CR ; n = 5 ) , AR + CR ( n = 4 ) , recurrent IgA nephropathy ( n = 5 ) , normal findings ( n = 2 ) , minimal - type chronic <span class="chemical">FK506</span> nephropathy ( n = 9 ) , and mild - type <span class="chemical">FK506</span> nephropathy ( n = 11 ) . 