2001
METHODS : This review discusses our current understanding of the mechanisms of TGF - beta signaling , focusing on the roles of TGF - beta in regulation of vascular wall cells and on the regulation of TGF - beta superfamily signals by inhibitory Smads .
 vascular wall cells
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Anatomy 
Text: {0} 
Answer:
 vascular wall cells