HAS2 expression is regulated in several fashion [57], either by secreted factors like TGFβ, interleukin-1β, fibroblast growth factor-2 (FGF-2), platelet-derived growth factor (PDGF), keratinocyte growth factor (KGF), epidermal growth factor (EGF) [58] or by post translational modification as ubiquitination, O-GlcNAcylation, phosphorylation [37,59,60], by epigenetic events [50] and other potential molecule(s) [61] secreted by tumour cells may influence its activity. This evidence concerns the gene TGFB1 and neoplasm.