762
However , limitations of beta - agonist therapy due to drug tachyphylaxis related to beta ( 2 ) AR desensitization , and recent findings regarding the manner in which beta ( 2 ) ARs and cAMP signal , have raised new and interesting questions about these well - studied molecules .
 Chemical: cAMP
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: cAMP