SRGN and breast cancer: As an extracellular matrix (ECM) component, serglycin participates in packaging secretory granules and regulates the storage or release of enzymes, serotonin and histamine in hematopoietic cells.14, 15 We first reported that serglycin promoted NPC epithelial-to-mesenchymal transition (EMT) and metastasis in an autocrine manner.16 Recent results showed serglycin promoted the aggressive phenotype of breast cancer cells metastasis and was associated with tumorigenesis in myeloma and acute myeloid leukemia.12, 17, 18, 19, 20