12640
The mechanism of reduced GR levels in relation to age and sport activity could involve a loss or an involution of receptor synthesis .
 protein: GR
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: cell line, protein, RNA, DNA, cell type 
Text: {0} 
 Entities: GR 
Answer:
 protein: GR