Ben Chan (Center for Phage Biology & Therapy, Yale University) and colleagues report the use of a personalized, inhaled phage therapy for treating P. aeruginosa infections in 9 CF adults, with the goal of selecting phages that target bacterial cell surface receptors that contribute to antibiotic resistance or virulence. Results showed that phage therapy: 1) reduced sputum P. aeruginosa, 2) showed evidence for predicted trade-offs in most subjects, and 3) improved lung function.