CD180 and systemic sclerosis: The therapeutic effects of intravenous immunoglobulins (IVIg) could partly be due to the appropriate pool of natural autoantibodies [29], and IVIg seems to be beneficial in SSc [30]; therefore, we also examined the effect of anti-CD180 and anti-CD180 and CpG co-treatment on the production of natural and pathologic autoantibodies of tonsillar B cells.