Clinical manifestations such as SGE, lymphadenopathy, palpable purpura, peripheral neuropathy and Raynaud phenomenon, serological features including RF and anti-Ro/SSA or/and anti-La/SSB autoantibodies positivity, monoclonal gammopathy, C4 hypocomplementemia, and cryoglobulinemia, as well as extensive lymphocytic infiltration in MSG biopsy (Tarpley score ≥3) were found to be associated with NHL development. This evidence concerns the gene SSB and monoclonal gammopathy.