8286
Furthermore , the levels of proteins involved in the maintenance of brain iron homeostasis , including ferritin , transferrin receptor 1 , and iron regulatory protein 2 , were significantly different at postoperative days 1 and 3 in the hippocampus of splenectomized animals when compared with those of the control .
 Chemical: iron; Chemical: iron
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: iron, iron 
Answer:
 Chemical: iron; Chemical: iron