16294
Reports indicating the levels of oxysterols in plasma , cerebrospinal fluid and various tissues are in many cases unrealistic owing to a lack of attention to the possibility of autoxidation , a process by which oxysterols are formed from cholesterol by oxygen in air .
 Chemical: oxysterols; Chemical: oxysterols; Chemical: cholesterol; Chemical: oxygen
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: oxysterols; Chemical: oxysterols; Chemical: cholesterol; Chemical: oxygen