5797
Induction of endothelial adhesion molecules by the cytokine tumor necrosis factor-alpha ( TNF ) can occur independently of protein kinase C and activation of a protein tyrosine kinase ( PTK ) has recently been implicated in the upregulation of vascular cell adhesion molecule 1 ( VCAM-1 ) by interleukin-4 ( IL-4 ) on endothelial cells .
 endothelial cells, protein tyrosine kinase, protein kinase C, IL-4, vascular cell adhesion molecule 1, tumor necrosis factor-alpha, endothelial adhesion molecules, PTK, TNF, VCAM-1, interleukin-4, cytokine
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:
 endothelial cells, protein tyrosine kinase, protein kinase C, IL-4, vascular cell adhesion molecule 1, tumor necrosis factor-alpha, endothelial adhesion molecules, PTK, TNF, VCAM-1, interleukin-4, cytokine