Assertion: rheumatoid arthritis | /r/HasProperty | the lining of the membranes
Facets:
Source sentences:
text: Rheumatoid arthritis occurs when your immune system attacks the synovium — the lining of the membranes that surround your joints.
text: Rheumatoid arthritis occurs when your immune system attacks the synovium — the lining of the membranes that surround your joints.