7701
When these facts are combined with the fact that none of the studies were conducted with rigorous randomization or ' blinding ' procedures ( implying the possibility of ' operator bias ' ) one must conclude that there is no indisputable bioassay evidence that vertebrate sex steroids have endocrinological or reproductive roles in mollusks .
 steroids
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 steroids