Researchers from the US, Japan, and Turkey describe germline changes in the Bloom syndrome-related gene that appear to boost mesothelioma risk in individuals exposed to asbestos. Starting with 10 familial mesothelioma patients from four affected families in Turkey, the team used genome sequencing to focus in on a truncating frameshift mutation that affected one copy of the BLM gene in a mother and son with mesothelioma from one of the families.