Pineal gland organoids illuminate human melatonin and circadian regulation.

Human pineal development and neuroendocrine regulation remain incompletely understood at the molecular and functional levels. Kiral et al.1 establish human pineal gland organoids (hPGOs) that recapitulate pinealocyte maturation, noradrenergic responsiveness, and melatonin synthesis, providing a platform for investigating circadian dysfunction and disease-associated sleep disturbances.