STEAP4 and neurodegenerative disease: Importantly, Lipocalin-2, Steap-4, and Spp1 (the 2nd, 3rd, and 4th most-highly expressed genes in NSPCs co-cultured with platelets), as well as Serpina3, are all pro-inflammatory molecules75,85–88 that have been linked to neurodegenerative diseases, such as multiple sclerosis87,89,90, while Lipocalin2 and Steap4 are also involved in the all-important regulation of iron metabolism.