2753
Taken together , these results led us to conclude that E . cava regulated the expression and activity of gamma - secretase and alpha - secretase , leading to a reduction in A beta production by the stable cells .
 None
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