Tularemia is a rare but highly infectious disease caused by Francisella tularensis, a bacterium that can evade immune defenses. Symptoms of infection can include fever, swollen lymph nodes, and—in some cases—pneumonia. What makes the pathogen especially concerning is how little it takes to cause infection—fewer than 10 bacterial cells can be enough. Scientists at Arizona State University have taken a key step toward understanding how this bacterium survives inside the human body. For the first time, the team has isolated and studied a set of proteins that play a central role in infection, revealing a potential weakness that could eventually be targeted with new treatments. The study is published in the journal Biochimica et Biophysica Acta (BBA)–Biomembranes.