Alternative preventative options include the screening of newborns, and appropriate follow-up, for TEL-AML1 and other pre-disposing genetic abnormalities [79,80], although recent evidence suggests that the frequency and/or levels of the TEL-AML1 positive cells may be lower than previously reported [79,81]; or controlling levels of natural background ionising radiation, which may account for 20-30% of childhood leukaemia cases [82-84]. This evidence concerns the gene RUNX1 and leukemia.