Four contributors—WT1, TRIM28, REST, and 11p15 epimutations and uniparental disomy that result in biallelic IGF2 expression—each account for about 2%.2, 4, 5 The remaining 17 are very rare and, together, probably account for no more than 2% of unselected Wilms tumours.2, 3, 4, 6, 7, 8, 9, 10, 11 Functional enrichment analysis highlighted nucleic acid metabolism, chromosome organisation, chromatin or histone modification, and negative regulation of cellular processes as important pathways underlying Wilms tumour predisposition (appendix). This evidence concerns the gene WT1 and Wilms tumor.