Task: Answer Verification
Input (English): Question: Are high expression levels of the B cell chemoattractant CXCL13 in rheumatoid synovium a marker of severe disease?
Answer: Synovial CXCL13 appears to be a marker of a more severe pattern of RA disease, characterized by increased lymphocyte activation and bone remodelling beyond the level of conventional markers of inflammation.
Output (English): yes