8344
In contrast, the beta isoform is expressed at very low constitutive levels in both cell types but is only up-regulated in response to mast cell activation signals delivered through the FcepsilonRI or via calcium ionophores .
 ( protein: FcepsilonRI, None) , ( protein: beta isoform, None) 
Locate the role in the text that participated in the event based on the event type and return it in the event list. 
 Option: Event type: RNA,cell type,protein,cell line,DNA, Arguments type: . 
Text: {0} 
Answer:
 ( protein: FcepsilonRI, None) , ( protein: beta isoform, None) 