Numerous early studies in both rodent models and humans have also documented concurrent increases in serum protein sialylation and sialyltransferase activity during malignancy, including in multiple myeloma, implying that ST6GAL1 expressing tumor cells are capable of secreting enzyme into the extracellular pool (Bernacki and Kim, 1977; Cohen et al., 1989b; Cohen et al., 1993; Chelibonova-Lorer et al., 1986; Dairaku et al., 1983; Gessner et al., 1993; Poon et al., 2005). Here, ST6GAL1 is linked to plasma cell myeloma.