7499
However, p38 MAPK is activated strongly and synergistically by either CD3/CD28 coligation or PMA/Ca2+ ionophore stimulation , which mimics TCR - CD3/CD28 -mediated signaling .
 CD3/CD28, TCR, p38 MAPK, CD3/CD28
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:
 CD3/CD28, TCR, p38 MAPK, CD3/CD28