If these mutations occur in a common precursor and drive tumour development by influencing differentiation direction, then this may explain why Group 1 tumours, enriched for BRAF-V600E mutations display an astrocytic expression phenotype, while Group 2 tumours display an oligodendrocyte precursor enrichment alongside frequent FGFR1 mutations. This evidence concerns the gene FGFR1 and neoplasm.