PRDM9 and plasma cell myeloma: Interestingly, although expression levels RNASET2 in MM patients does not change much from its precancerous Monoclonal Gammopathy of Undetermined Significance stage, recent evidence suggest that this gene is significantly regulated by epigenetic modifications, as observed in t(4;14)+ myeloma cells overexpressing the histone methyltransferase MMSET, a driving factor in the pathogenesis of this subtype of myeloma.