PFAS chemicals, which have turned up in drinking water in cities across the US, have been linked to non-Hodgkin’s lymphoma and kidney, testicular, prostate, breast, liver, and ovarian cancers. A new study is going one step further to try to explain how some of these PFAS compounds, a family of thousands of synthetic chemicals that have been used for decades in everything from food packaging to nonstick cookware, might cause cancer on a molecular level. This group of chemicals is also prevalent in firefighting foam (Class B) and firefighter PPE (turnout gear); and firefighters have been shown to have a higher incidence than normal of the associated cancers.