For example, the HA receptor CD44 is misexpressed in Sdc-1-depleted breast cancer cells [16], and MDA-MB-231 breast cancer cells depleted of beta4GalT-7, a biosynthetic enzyme generating the HS GAG attachment site, respond with a reduced expression of Sdc-1 and an upregulation of HA biosynthesis. This evidence concerns the gene SDC1 and breast cancer.