HAS1 and neoplasm: Curved protruding membranes increase the cellular surface area, which is important for absorption, transport, environmental sensing, secretion, pinpoint delivery of cargo between cells, antibody–antigen recognition, etc. Mucins, HA, and HAS are highly represented on cell protrusions such as the microvilli of oocytes and mesothelium [79,80], neuronal axons [81], as well as tumor cells, enterocytes, astrocytes, and dendritic cells.