18517
Many progesterone ( P4 ) effects are mediated by its intracellular receptor ( PR ) , which has two isoforms , PR - A and PR - B , each of them with different function and regulation .
 Chemical: progesterone
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: progesterone