11076
EXPERT OPINION : To date , all of the pathway inhibitors that have entered clinical trials and the majority of compounds identified via high - throughput screens target smoothened ( Smo ) , a transmembrane protein that is essential for pathway signaling .
 None
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 None