Among the 27 infratentorial pilocytic astrocytomas, 25 (92.6%) had BRAF duplication, and within the eight supratentorial midline pilocytic astrocytomas, six also harboured BRAF duplications (75%), and one tumour showed whole chromosome 7 gain in the absence of focal duplication (Figure 4B). This evidence concerns the gene BRAF and pilocytic astrocytoma.