When can tuberculosis therapy be stopped without risk of relapse? Doctors are faced with this question time and again, because the lack of detection of the tuberculosis pathogen Mycobacterium tuberculosis is no guarantee for a permanent cure of the lung infection. Patients who respond to the standard therapy may be out of treatment after six months. But for resistant cases, more than 18 months of treatment duration is currently advised. “This is a very long time for those affected, who often have to take more than four antibiotics every day and suffer from side effects,” explains Prof. Dr. Christoph Lange, Clinical Director at the Research Center Borstel and director of the study, conducted at the German Center for Infection Research (DZIF) in cooperation with the German Center for Lung Research (DZL). “We urgently need a biomarker that enables the implementation of an individualized treatment duration,” he emphasizes. After all, not every patient needs so long to recover.