5379
Although prior studies suggest a role for protein tyrosine kinases and phosphatases in Fas signaling , we report here that Fas ligation induces apoptosis in T cells deficient in either CD45 or Lck .
 T cells, protein tyrosine kinases, Lck, Fas, CD45
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:
 T cells, protein tyrosine kinases, Lck, Fas, CD45