2665
Two of these cell cycle inhibitors , p16 ( INK4A ) and p15 ( INK4B ) , have tumor suppressor activities and are inactivated in human cancer .
 cell, tumor, cancer
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Anatomy 
Text: {0} 
Answer:
 cell, tumor, cancer