At the cellular level, PARP1 inhibition most prominently reduced fibroblast, macrophage and T-cell numbers in infected mouse lungs (Fig. 4, Supplementary Fig. 6) which are fundamental components of the hallmark TB granuloma, an immune structure that limits the spread of M.tb but may inadvertently hinder immune- or antibiotic-mediated bacterial killing5,24,65. Here, PARP1 is linked to tuberculosis.