Altos Labs disclosed work testing rejuvenation therapies in organs maintained ex vivo, advancing its program to evaluate anti‑aging interventions outside the body. The company is reportedly using organ perfusion systems to keep tissues viable longer, enabling direct testing of candidate cell‑reprogramming and rejuvenation molecules on intact human and animal organs. The approach aims to accelerate preclinical proof‑of‑concept by observing organ‑level responses to interventions and could shorten development timelines for translational leads. Independent experts note ex vivo organ testing raises technical, regulatory and ethical questions but could provide high‑fidelity data to prioritize in vivo studies.