2783
At low concentrations of CYP2E1 , the apparent K ( M ) of CYP2B4 for CPR increased up to 23 - fold with virtually no change in the k ( cat ) for the reaction , however , at higher concentrations of CYP2E1 , the apparent K ( M ) of CYP2B4 for CPR decreased to levels similar to those observed in the absence of CYP2E1 and the k ( cat ) also decreased by 11 - fold .
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Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 None