4765
Subsequent studies , such as tissue and age specific modulation of Lin28b and Lin28a expression , could determine whether the expression patterns observed are responsible for modulating the onset of puberty and delineate further the role of this pathway in the HPG axis .
 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