Serum protein fingerprints associated with MGUS and MM and their changes in MM 
after autologous stem cell transplantation (MM-ASCT, day 100) remain unexplored. 
Using highly-sensitive Proximity Extension ImmunoAssay on 92 cancer biomarkers 
(Proseek Multiplex, Olink), enhanced serum levels of Adrenomedullin (ADM, Pcorr= 
.0004), Growth differentiation factor 15 (GDF15, Pcorr= .003), and soluble Major 
histocompatibility complex class I-related chain A (sMICA, Pcorr= .023), all 
prosurvival and chemoprotective factors for myeloma cells, were detected in MM 
comparing to MGUS. Comparison of MGUS and healthy subjects revealed elevation of 
angiogenic and antia-poptotic midkine (Pcorr= .0007) and downregulation of 
Transforming growth factor beta 1 (TGFB1, Pcorr= .005) in MGUS. Importantly, 
altered serum pattern was associated with MM-ASCT compared to paired MM at the 
diagnosis as well as to healthy controls, namely by upregulated B-Cell 
Activating Factor (sBAFF) (Pcorr< .006) and sustained elevation of other 
pro-tumorigenic factors. In conclusion, the serum fingerprints of MM and MM-ASCT 
were characteristic by elevated levels of prosurvival and chemoprotective 
factors for myeloma cells.