9253
Considering the immunosuppressive effect of ptaquiloside , we hypothesized that two genes involved in cellular ion homeostasis , metallothionein 1 ( Mt1 ) and metallothionein 2 ( Mt2 ) , could be implicated because Mt1 and Mt2 are responsible for zinc homeostasis , and a reduction of free intracellular zinc impairs NK functions .
 Chemical: ptaquiloside; Chemical: zinc; Chemical: zinc
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: ptaquiloside; Chemical: zinc; Chemical: zinc