Recently it has been shown that SFT cells have a markedly greater expression of IGF-II mRNA and a lesser expression of pro-hormone convertase 4 [PC 4] mRNA in the tumour tissue compared to normal placental tissue, raising the possibility that defective PC4 gene expression in these tumours may underlie the impaired processing of IGF-II [26]. This evidence concerns the gene IGF2 and neoplasm.