Phenotypically, EMP, SBP, and MM are very similar, but EMP shows less frequent expression of CD56, usually absence of cyclin D1 (and the t(11;14) translocation), and a lower proliferation rate as compared to extramedullary manifestations of multiple myeloma, which usually represent an aggressive terminal stage of disease and may show high MYC expression and TP53 aberrations [33]. This evidence concerns the gene NCAM1 and plasma cell myeloma.