2219
Analysis of 12 - week - old female k . i . mice revealed increased levels of biochemical bone formation and resorption markers in apoE2 k . i . animals as compared to apoE3 k . i . and apoE4 k . i . , with a reduced osteoprotegerin ( OPG ) / receptor activator of NF - kappa B ligand ( RANKL ) ratio in apoE2 k . i . , indicating increased turnover with prevailing resorption in apoE2 k . i .
 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