An overview of SULF gene expression in human cancers indicates that although SULF1 is sometimes downregulated (Khurana et al., 2013), more often SULF1 and/or SULF2 are overexpressed in tumours, which can be associated with a worse prognosis (Lemjabbar-Alaoui et al., 2010). This evidence concerns the gene SULF1 and neoplasm.