Human aspartate/asparagine-β-hydroxylase (AspH, BAH, HAAH) belongs to the family of 2-oxoglutarate (2OG) dependent oxygenases1 and catalyses the post-translational hydroxylation of specific aspartyl- and asparaginyl-residues in human epidermal growth factor-like domains (EGFDs) using 2OG and O2 as co-substrates and Fe(II) as a cofactor (Fig. 1).2, 3 Hypoxia is reported to regulate the expression levels of human AspH4, 5 and upregulated levels of AspH have been detected on the cell surface of invasive human cancers such as hepatocellular carcinoma,6, 7 breast cancer,8 and pancreatic cancer.9 Here, ASPH is linked to breast cancer.