In a multicentre, population-based, case-control study, Concannon suggested that four common variants of ATM (c.1899-55T>G; c.3161C>G; c.6348-54T>C and c.5558A>T) were associated with a lower contralateral breast cancer risk (overall RR 0.8, 95% CI 0.6–0.9) compared to those with rare, missense ATM mutations. This evidence concerns the gene ATM and breast cancer.