4412
In contrast, we found that AR can initiate apoptosis in S49 cells after treatment with 5 alpha-dihydrotestosterone , despite its relative inability to induce high level expression of MMTV .
 S49 cells, AR
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: cell line, protein, RNA, DNA, cell type 
Text: {0} 
Answer:
 S49 cells, AR