6892
Similarly to inactivating mutations in other key regulators of HR repair , Rnf4 deficiency leads to age - dependent impairment in spermatogenesis .
 None
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities:  
Answer:
 None