As of this review, there are no characterized zebrafish mutants of either atm or atr. Based on the above studies, null mutants may have strong phenotypes and generation of both null and precise point mutants would help identify the spectrum of potential developmental and cancer predisposition phenotypes of ATM and ATR mutations in zebrafish to discern the relative roles of these kinases in genome stability maintenance and tumor suppression. The gene discussed is ATR; the disease is cancer.