1747
alpha 4 integrins mediate cell-cell and cell-extracellular matrix interactions that are critical for maturation and function of the immune system as well as differentiation of skeletal muscle .
 alpha 4 integrins
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:
 alpha 4 integrins