FAS and lymphoma: Several serum biomarkers for lymphomas have been suggested as being clinically useful: cystatin C [6], soluble intercellular adhesion molecule-1 (s-ICAM-1/s-CD54) [7], soluble Fas/CD95/APO-1 [8], soluble tumor necrosis factor receptor 2 (sTNF-R2) [9], soluble interleukin-2 receptor (sIL-2R) [10], nm23-H1 protein [11], and soluble CD44 [12].