In a recent study, significantly elevated levels of plasma ubiquitin and proteasome enzymatic activities (encompassing of chymotrypsin-like (Ch-L), trypsin-like (Tr-L) and caspase-like activity) were found in pre IFN-ß treated MS patients compared to healthy controls (p-value <0.01). The gene discussed is RPS27A; the disease is myeloid sarcoma.