CD40LG and rheumatoid arthritis: Though some preliminary evidence suggests that mannose receptors may be overexpressed on immune cells of the myeloid lineage present in blood and synovial tissue from RA patients [33], as an important secreted soluble PPR family, the levels of mannose-binding lectin (MBL), an opsonic factor binding to HSV, were found to be decreased in eRA; this is associated with a higher risk of developing early erosive RA and higher levels of IgM RF and CRP [34,35], and the MBL gene is down-regulated more than threefold compared with late-stage RA [36].