HS2ST1 and breast cancer: In this scenario, we aimed to elucidate the influence of HS2ST1 and HS3ST2 HS sulfotransferases on the acquisition of a CSC phenotype and the expression of BCSC markers in two distinct breast cancer cell lines, MDA-MB-231 (triple negative, mesenchymal phenotype) and MCF-7 (ER+/ PR+/HER2−, epitheloid morphology).