PTN and glioblastoma: Among them, IL‐10 significantly reduces the effect of antitumor therapy by inhibiting the antitumor immune response mediated by chemotherapeutic drugs.[34] TAMs in glioblastoma tumor tissues secrete a large amount of pleiotrophin (PTN) protein, while glioblastoma cancer stem cells (CSCs) contain a large amount of its receptor PTPRZ1.