In addition, the NPC proteome included factors known to be associated with NSC/NPC maintenance, survival, and proliferation, such as PDGF, TGF-β, VEGFB, insulin-like growth factor binding protein 3(IGFBP3) family, plexin-B2 (PLXNB2) and secreted phosphoprotein 1 (SPP1) (data not shown). Here, SPP1 is linked to nasopharyngeal carcinoma.