We are a translational research laboratory at UCSF and the San Francisco VA studying why transplanted lungs become injured, why some injuries heal while others progress, and how molecular information can be used to recognize and treat rejection earlier. Long-term success after lung transplantation is limited by chronic lung allograft dysfunction, or CLAD, a lasting loss of graft function that affects roughly half of recipients within five years. The tools used to monitor transplanted lungs can show that function is declining, but they often cannot show which biological process is causing the damage, and by the time decline is obvious, the airway injury may already be fixed. Our work aims to move lung transplantation away from late recognition of graft failure and toward earlier biological diagnosis, so that treatment can be matched to the mechanism actually driving the injury.