CXCL13 and B-cell chronic lymphocytic leukemia: In particular, sCD23 serum levels have been previously linked to early development of BCL, especially of CLL.27 CXCL13 serum levels have been previously linked to DLBCL development.27 sBCMA and SLAMF7 plasma levels have been previously linked to MGUS and progression to MM.32,33,36 Additionally, some of the other identified candidate proteins overlap with markers of active disease.