As examples, HS3ST2 was reported to be critically involved in breast cancer cell invasiveness [14]; high expression of HS3ST3B induces epithelial-mesenchymal transition in pancreatic cancer cells [15] and promotes the proliferation of acute myeloid leukemia cells [16]; the pathological expression of HS3ST4 plays a deleterious role in the escape of cancer cells to the immune system [17]. Here, HS3ST2 is linked to breast cancer.