ARPA-H’s LIGHT program seeks better ways to diagnose and monitor lymphatic dysfunction, a condition that can be difficult to identify because symptoms may be subtle and existing methods have limitations. Its research areas include biomarker discovery, imaging, and approaches using genetics, epigenetics, and models of lymphatic dysfunction. The program also incorporates patient and caregiver perspectives: performer teams include a Discovery Duo pairing an early-career investigator with a patient or caregiver ambassador, and teams may gather broader community input through voice sessions.