206
In vivo , mutant embryos do not exhibit increased apoptosis but show reduced cell proliferation accompanied by decreased expression of cyclin E and mdm - 2 , a regulator of p53 activity .
 None
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Disease 
Text: {0} 
Answer:
 None