Starting from low-grade pylocytic astrocytoma, grade I and astrocytomas, grade II towards the more invasive anaplastic astrocytomas, grade III and GBM, grade IV, a progressive up-regulation of TRPML-2 mRNA expression was detected by qRT-PCR compared with NHA samples (Figure 2), with a strong increase (about 45-fold) of TRPML-2 expression in GBM biopsies, compared to pilocytic astrocytomas. This evidence concerns the gene MCOLN2 and pilocytic astrocytoma.