This biochemical phenotype is intermediate between the established epinephrine producing tumours due to NF1 and RET variants and the phenotype of norepinephrine tumours harbouring VHL or SDHB/D variants; this diagnostic phenotype is explained by a significant but limited capacity to produce epinephrine due to the intermediate tissue expression of mRNA for PNMT (11). This evidence concerns the gene NF1 and neoplasm.