While a paediatric cancer predisposing tumour suppressor gene commonly mutated in retinoblastoma and to a lesser extent osteosarcoma61, and less common as an adult cancer predisposing gene62, RB1 is recognised as one of five most prevalent somatically mutated genes in metastatic cancers63, with RB1 loss in prostate tumours associated with poor patient outcomes64. This evidence concerns the gene RB1 and cancer.