8504
Western blot analyses showed significant effects of Pb exposure on DNMT1 , DNMT3a , and MeCP2 expression , with effects often seen at the lowest level of exposure and modified by sex and developmental window of Pb exposure .
 Chemical: Pb; Chemical: Pb
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: Pb; Chemical: Pb