Although the hydrodynamic radii of immunoglobulin monomers (IgG—5.29 nm; IgA—6.50 nm; IgM—12.6 nm), as well as their proteolytic fragments (F(ab′)2—4.48 nm; Fc—3.19 nm; Fab—2.19 nm), are known [45], we cannot predict the molecular composition of dominant RA CIC colloidal particles identified in our study. This evidence concerns the gene CD40LG and rheumatoid arthritis.