ST8SIA4 and chronic myelogenous leukemia, BCR-ABL1 positive: Recent studies have shown that ST8SIA4 mRNA had the highest level of expression and was a major factor in the high levels of 2,8-linked NeuNAc residues on the PBMC surfaces of CML/MDR patients, but ST8SIA6 expression was at a high level in CML patients, indicating ST8SIA6 to be an essential factor in the emergence of malignant changes.