6860
Thus, the photoproducts of tryptophan are suggested to be mediators of light via binding to the Ah receptor and as such also could have a role in light-regulated biological rhythms .
 protein: Ah receptor
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: Ah receptor 
Answer:
 protein: Ah receptor