Apart from their surface expression, the soluble form of CD27 (sCD27) is extracellularly released upon TCR activation via proteolytic cleavage of membrane-bound CD27 by metalloproteinase (37), which is evident in the clinical specimens of patients with autoimmune inflammatory diseases such as rheumatoid arthritis (RA) (38)and systemic lupus erythematosus (SLE) (39). The gene discussed is CD27; the disease is systemic lupus erythematosus.