HYAL1 and breast cancer: To determine the functional consequences of forcing HYAL1 expression in human breast cancer cells, we generated the breast cancer cell lines MCF7 and ZR-75-30 with upregulation of HYAL1 by stable transfection with HYAL1 expression vector (termed MCF7-HYAL1 and ZR-HYAL1) or the empty pcDNA3.1 vector (designated MCF7-Vec and ZR-Vec), respectively.