KIT and pilocytic astrocytoma: Patients diagnosed at a young age with pilocytic astrocytoma usually had moderate or strong tumor endothelial cell KIT expression, whereas those diagnosed at an older age had no or only faint KIT expression in the tumor endothelial cells (Kruskall–Wallis test P = 0.0012, Figure 2, upper panel; when analyzed moderate or strong expression vs. negative or faint expression using the Mann–Whitney test P = 0.0001).