1526
Hence , the down - regulation of p21WAF1 , together with the alterations in Bax and cdk2 as observed in our studies , may define a novel mechanism by which ciprofloxacin inhibits tumor cell growth and induces apoptotic cell death .
 tumor cell, cell
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Anatomy 
Text: {0} 
Answer:
 tumor cell, cell