7310
Percent identities of the mouse PP2 to mouse Y1 , mouse Y4 / PP1 and human Y2 receptors are 53 , 42 , and 31 , respectively .
 mouse PP2, mouse Y1, Y4, PP1, human Y2 receptors
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
 mouse PP2, mouse Y1, Y4, PP1, human Y2 receptors