DDX1 and neoplasm: We have also shown that there does not appear to be any increased incidence of childhood tumours when DDX1 alone is duplicated.<h4>Funding</h4>UCL Great Ormond Street Institute of Child Health Child Health Research CIO PhD Studentship, Brain Tumour Charity, Children with Cancer UK, Great Ormond Street Hospital Children's Charity, Olivia Hodson Cancer Fund, Cancer Research UK and the National Institute for Health Research.