454
We observe the agonist - induced up - regulation of ADRB2 and already in 2005 , the FDA warned patients that ADRB2 might be down - regulated ( desensitization ) and be unresponsive for asthma treatment due to long - acting agonist exposure [ 20 ] , [ 30 ] .
 None
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Anatomy 
Text: {0} 
Answer:
 None